Dr Bacon-Shone said he had always remained true to his ethical and scientific obligations to develop honest science and to distribute it openly, irrespective of funding.

'To my knowledge I have never met anyone working for a tobacco company. To my knowledge, John Rupp was a lawyer for the funding source. I do not question where the funds come from. I ask 'is it ethical, is it advancing science and truth?' My conscience is clear. I have never done anything unethical.

'I feel very strongly I have never done anything I should feel ashamed about. I agree violently that smoking is a serious health risk, that the tobacco industry can't be trusted and has lied, but as a scientist I think that passive smoking has been the subject of a lot of bad science.' Dr Bacon-Shone said he had presented at a tobacco-sponsored conference in Lisbon a paper which questioned the findings of Japanese Professor Hirayama, who years earlier had found a high correlation between environmental tobacco smoke (ETS) and lung cancer in non-smokers. Professor Hirayama's findings were devastating for the tobacco industry. Dr Bacon-Shone said he was not paid for presenting his paper, which he agrees would have been 'music to the ears' of the tobacco industry.

'It would be unfortunate if there was the implication that it was contrived. But the key point is: does what I wrote stand up? Yes, it does, so I have no regrets on writing the paper. My position is clear: the evidence that tobacco is a health hazard is overwhelming, but the work by Professor Hirayama and others overstated the risk of ETS and that's a scientific issue. That's why I was happy to write the study on Hirayama.

'ETS is a health hazard, but let's be frank - one of the major reasons people want to get rid of it is that it's so obnoxious. But we should not try to use biased findings based on science that is not of the finest quality to drive the policies we desire. If we allow the ends to justify the means, where do we stop? 'Any industry that thinks the risk of their product is overstated by poor research clearly has an interest to address that and I think there's nothing unethical in doing that. If someone asked me to do a study and said 'we will decide whether to publish or not', then I would not do it. But if someone offers me money to present my research somewhere, then I think it's perfectly ethical for me to present it - irrespective of the funding.

'To me it makes no difference if the money comes from COSH (Council on Smoking and Health) or Philip Morris. The problem would be if you were only funded to do a certain kind of work, or if the results were unfavourable and could not be released.

'The separate issue is whether the funding body should hide. Quite clearly, the tobacco industry was paying people to do certain things and they had a PR mechanism [to promote those things]. It's unethical for them not to reveal who the ultimate funding source is.

'They have clearly used the research that we did to try to push a particular line. The main unethical point was simply hiding. They hid lots of things. I'm very unhappy about the implications that I'm a stooge. Nobody was paying me to do something that I did not already feel. I'm sure that they picked on all of us because they felt we would take a particular independent line.' Dr Bacon-Shone said the tobacco documents and their allegations of his involvement were distressing. 'I think that clearly, this shows [scientists] need to be more wary and not always believe everything you're told.' Linda Koo By researching and publishing a number of studies relating to dietary factors in lung cancer, Dr Linda Koo Chih-ling was known to tobacco industry scientists and chiefs as early as the mid-1980s. Internal company memos and documents refer to her work as a researcher in the University of Hong Kong's department of community medicine and in the Hong Kong Anti-Cancer Society, as well as her collaboration for several years with Swedish scientist Dr Ragnar Rylander.

Dr Koo's studies found a high rate of lung cancer among children and women in Southern China and Hong Kong who had never smoked, suggesting that indoor pollution and diet were the biggest factors. Her published papers from the 80s include, Is Passive Smoking An Added Risk Factor For Lung Cancer In Chinese Women? and Measurements Of Passive Smoking And Estimates Of Lung Cancer Risk Among Non-Smoking Chinese Females.

Dr Koo, whose work at the university was complicated by a plagiarism case she won against colleague Dr T H Lam, is now working at the American Health Foundation in New York and studying prostate and lung cancer.

She told the Post she had never been a paid consultant to the tobacco industry. She said she was unaware that Professor Rylander, with whom she met several times in Hong Kong and abroad, was one of the tobacco industry's highest-paid consultants, receiving US$150,000 a year in the early 90s.

'The point is if I'm doing work with Ragnar and if I'm happy with my work for him, that's OK. Who is he working with? That's none of my business.

'I don't go round asking people their financial sources. I knew he did lots of work on air pollution. We are clear on our own agenda. Let's get the politics out of this. This is not the Middle Ages. It's not the Inquisition. The more the politics, the less the science. Too many people have gone overboard about ETS. It's no different from burning a leaf. I mean, tobacco is just a leaf.

'The point is this - there are forces on all sides. For active smoking, it's quite clear there's a link with lung cancer. Passive smoking is a much more fuzzy issue, there's a lot of politics mixed up in the science. It's not like cavorting with the devil to meet people from the tobacco industry. We have to get the hysterics out of this. I'm a scientist. I can't be selective about who I will speak to. We have to deal with lobbyists all the time. We stick to what our research indicates. As a scientist, our integrity is bound up in presenting the data as shown. We will all be judged by time.' Dr Koo said she attended some indoor air conferences. 'I know that at some of the conferences, there was some [tobacco] industry money involved. That's nothing new. But we were certainly not paid to say that smoking is wonderful. I get invited to conferences all over the world. You would be paid an honorarium for speaking. An honorarium is a fee that's paid for a lecture. I don't consider that as being a paid consultant.

I believe a paid consultant would be someone who has a contract to do a research project. We did not get huge amounts of money [for attending conferences]. I'm sorry, a few hundred dollars would not buy me off. I certainly did not have meetings with [tobacco industry figures] saying 'you would do this or do that'. They knew my door was open. I do research they are interested in and I have a line they find very politically satisfying. As a scientist I give information out. I was not being paid.' Dr Koo said she regretted that a confidential letter she wrote in 1988 to Y Y Tang, then of the Tobacco Institute, had ended up in the Philip Morris' archives and been made public. The two-page letter from Dr Koo pinpoints specific weaknesses in a study and report by Dr T H Lam on passive-smoking risks.

'I was not paid for that, it was just my opinion,' said Dr Koo.

'In terms of ETS, [tobacco companies] would be interested in my studies but that doesn't mean I was funded by them. There were findings they would have been happy with. We were working since 1980 on why there was a high rate of lung cancer in non-smoking Chinese women, looking at all possible sources of pollutants, and we found no relationship to ETS.

'In any case, I think whoever is putting up money for research, it helps expand the picture. I don't think because something is paid for by someone, it is scientifically unrigorous. If people are falsifying data, then they will be shown up. Their results won't be repeated.' Dr Rylander told the Post from Sweden that he was a scientific adviser rather than a consultant to the tobacco industry and that he told Dr Koo: 'Don't touch that money.' He said Dr Koo probably would not have known he regularly informed Philip Morris about various aspects of Dr Koo's work in Hong Kong.

JOHN RUPP Lawyer John Rupp helped to set up and run the Asia ETS Consultants Programme for cigarette giant Philip Morris and several other leading tobacco companies. He has been openly acting for the US Tobacco Institute and the industry since the early 1980s, years before his contact with Hong Kong scientists.

Many of the once-confidential memos relating to work by Dr John Bacon-Shone and Dr Sarah Liao Sau-tung were written by Mr Rupp. He told the Post from Paris that Dr Bacon-Shone and Dr Liao were paid consultants to the tobacco industry and they knew this from the outset. He said Dr Koo was not a paid consultant.

'We have consulted at various times with John Bacon-Shone and Sarah Liao, but not for several years. Certainly they did receive some financial support for research, or else it never gets done.' Asked about the tobacco-funded Centre for Indoor Air Research (CIAR), Indoor Air International and the journal Indoor Air, which Dr Liao and Dr Bacon-Shone were involved in through research or membership, Mr Rupp said there was no attempt to hide from the scientists the source of funding.

'Everyone with whom we dealt knew from the very beginning our clients were tobacco companies and so the source of any funding they would receive would be coming from tobacco companies. You cannot deceive people or withhold information potentially significant to them.

'Yes, [Drs Bacon-Shone and Liao] would have known they were consulting to the tobacco industry. Because I told them. There is no way a scientist would fail to ask 'who is your client?' I would have told them before they asked. The clients in all cases were tobacco companies. I would be terribly, terribly surprised if anyone with whom I dealt took the view they didn't know it was tobacco [money]. Who would they think my client would be? 'In Sarah Liao's case [the money paid] was quite modest; in John Bacon-Shone's case it was even more modest.' Mr Rupp said the work of Drs Liao and Bacon-Shone was in two parts - general consulting and the indoor air study. 'At one point they said 'look, there is little research on indoor air quality, we need research', ' he recalled.

'They developed a proposal, submitted it to CIAR and they received funding. The funding in that case was from CIAR which had a great deal of tobacco support. I'm quite certain they knew CIAR was largely funded by tobacco companies.

'All the people who consulted with us expressed reservations about consulting to tobacco and the question they had was, 'if they did it, would they be subjected to unwarranted personal attacks? Would they be maligned or criticised by universities and interest groups?' We could not assure them that would not occur.' Asked about his memo describing the 'recruitment, education, orientation and deployment' of scientist consultants in Asia, Mr Rupp said: 'The fair reading is this - if you are going to seek advice from people you want them to have reviewed the literature and to make a significant time commitment to do that.' Asked if he wanted Drs Liao and Bacon-Shone to lobby on behalf of the tobacco industry, Mr Rupp said: 'I certainly encouraged them to share the results of their research with people who would be interested. Is that lobbying? I don't think so.' Hong Kong-based Philip Morris Asia vice-president Donald Harris, who was also closely involved between 1989 and early 1995, told the Post it was a costly venture in which 'consultants worked on a part-time, project basis on and off throughout the programme's duration'.

'To the best of my knowledge, the organisations and individual consultants associated with the programme were aware that it was funded by the tobacco industry, and were free to disclose this fact. I think that at no time were we trying to hide anything.' Mr Harris said that neither the programme's managers nor the tobacco companies 'exercised control over the content of presentations or papers prepared by consultants'. The consultants were 'encouraged to state whatever, in their professional judgment, they deemed appropriate about the science of ETS'.

Clive Turner, who headed the Hong Kong-based Asian Tobacco Council (ATC) in the early 90s, said from London: 'The ATC did not run the ETS programme, but, yes, I knew something of it and rather suspect that some of those [Asia consultant] scientists now wish with hindsight they had no connection with us at all. But at the time I'm sure they knew what they were doing.

'I don't know that scientists are that naive. For those scientists to say now, years later, they did not know the industry had a connection is in my mind disingenuous, to say the least.' SARAH LIAO The managing director of EHS Consultants, Dr Sarah Liao Sau-tung, has worked for private and public organisations, including BAT (British American Tobacco), the Consumer Council, the University of Hong Kong and the Hong Kong Government.

Among her most recent public work as an industrial hygiene specialist is a $10 million indoor air quality study, commissioned by the Environmental Protection Department in 1995 and completed last year. Her team for the study of air in 40 offices, cinemas, restaurants and other public places included Dr John Bacon-Shone.

In 1990 she received about $1 million from the Centre for Indoor Air Research (CIAR), which is almost wholly funded by the tobacco industry, to study indoor air in Hong Kong. She did this with the help of Dr Bacon-Shone.

'The study's one promising find was that nicotine levels from tobacco smoke were barely detectable, probably because the overall number of smokers was small and people tended to smoke outdoors,' the Post reported in 1991 after an interview with Dr Liao about her study's findings.

Dr Liao's CV includes her work from 1987 to 1996 with the Consumer Council. She is a Friends of the Earth governor, Broadcasting Authority member and has membership links with several other professional bodies.

In interviews with the Post, Dr Liao, a chemist, said she had never knowingly worked for the tobacco industry. She said she did not know at the time that the tobacco industry was paying her honorariums and expenses to attend symposiums on indoor air and passive smoking in Portugal, Canada and Thailand in 1990. She said she believed the money was coming directly from independent groups.

'They pay for the air fare, business class, and then they pay an honorarium, which is not much (less than US$3,000) - it would have just covered my costs,' she said. 'These meetings were mixed. Some doctors said smoking was not harmful and of course you knew it was all rubbish. On the other hand you had people . . . who lashed out at tobacco industries and the greed of governments who allowed them to exist.' Dr Liao emphatically rejected recent assertions by Philip Morris and its lawyer, John Rupp, that she was always fully aware she was being paid as a consultant to the tobacco industry. She said references to her in tobacco company documents were misleading and gross misrepresentations.

Dr Liao said she had always remained true to her ethical and scientific obligations to develop honest science and distribute it openly, including work she had done with Dr Bacon-Shone on tobacco-funded ETS-related issues. This work, she said, was peer-reviewed and conducted impartially and independently.

After publication of their CIAR study in Environmental Technology, she and Dr Bacon-Shone 'became aware the tobacco industry wanted [us] to lobby key people in Hong Kong [over second-hand smoke] and [we] rejected the attempts'.

She said Mr Rupp, a longtime tobacco industry lawyer with whom she had been in contact over the funding for her indoor air quality work, 'made it very clear to me that they wanted me to be a lobbyist'.

'It became clear to me later that Rupp also represented tobacco interests, although he was earlier known to me as representing the CIAR fund,' she said.

'I thought there must be something wrong, this is not my role. John [Bacon-Shone] and I talked when we both became suspicious and we both got out about the same time. I actually said to Rupp, 'I'm afraid I will not be the lobbyist that you want. As a consultant I work in factual stuff. It must be true to a scientific discipline, but I'm not your lobbyist.' They said 'if you don't want to do this we will find another consultant in Hong Kong'. I said 'fine'. ' Dr Liao said she had been for some time the subject of false innuendoes related to the tobacco industry and she welcomed the issue being publicised by the Post.

She said the tobacco industry documents naming her as a paid consultant and detailing what she had achieved for the industry were distressing. 'I work for all sorts of clients and we try very hard to be independent and our professional ethics are very important.' She rejected suggestions raised by a Philip Morris claim in one of the 1989 documents that she had made a Consumer Council presentation to disapprove restrictions on cigarette advertising. Dr Liao said she was a member of a council committee that made such a decision, but stressed it was a collective decision.