In his first in-depth interview since announcing his resignation in July, Dr Yeoh said he hoped his departure could bring closure to the tragic episode and help the Sars victims and their families put the sadness behind them.

'Whatever you say to them [patients and families] does not help,' he said. 'They also want to put an end to it. I understand their feelings. I don't have any ill-feeling towards them. This is the main reason for my resignation.'

Dr Yeoh became the first minister to assume political accountability when he resigned days after a Legislative Council select committee investigating the handling of the Sars outbreak published its findings. It was the third inquiry into the crisis.

The report stopped short of calling for health officials to be sacked. But the harsh criticism of Dr Yeoh by victims - he was called 'shameless' by one family at Amoy Gardens - turned the tide of public opinion against him.

Speaking to the South China Morning Post ahead of his departure, Dr Yeoh revealed he had told the chief executive he was willing to resign as a show of accountability in the early stages of the crisis. After the Legco report was published, he said, political pressure for him to stand down had eased.

In his resignation to Tung Chee-hwa, Dr Yeoh wrote: '... In order to demonstrate my political accountability and to bring a closure to this painful episode, I should resign as secretary for health, welfare and food.'

He told the Post he began to feel the wind of political change - the demand for accountability - in 1997 when the Hospital Authority he headed was badly hit by a string of medical blunders.

'You can't simply say our system has improved a lot if you have one blunder after another. I knew what was meant by political accountability. If you have to go, there's no point hanging on.'

Recalling the unfolding of the Sars crisis, Dr Yeoh said: 'From day one, I prepared myself psychologically. At the back of my mind, I knew Sars was a huge crisis. There would be recriminations.

'There're a lot of emotions [in such a crisis]. Emotion is hard to manage, it's unpredictable, irrational. There're no guidelines. When you need to go, you need to go.'

He said the Sars onslaught delivered a body blow to Hong Kong when visitors fled and the city lost contact with the world.

'The first thing on my mind was to get the whole thing under control as soon as possible. Other things were immaterial. [Given another chance,] I don't think I would do anything materially differently,' he said.

'I won't look back saying I should have done this or that. I will only review what could be done if the same thing happened again in future ... Mr Tung is quite worried about Sars coming back. I think it's not that difficult, relatively speaking.'

Dr Yeoh said the challenge remained how to deal with the unpredictability of known and unknown infectious diseases, but added: 'We have learned and have strengthened our system through measures such as the setting up of the Centre for Health Protection.'

Dr Yeoh joined the government in 1999 and stayed in the second Tung administration. He declined to say whether he had become a victim under the accountability system since lines of political and administrative responsibility remained unclear.

'It's a new and very young system. I hope there will be more in-depth debate on it,' he said.

He noted it would be difficult for people from the private sector with no public service experience to take up ministerial posts.

'These people are technocrats with no knowledge of the government system and politically untested. It's a steep learning curve and highly risky.'

Citing his experience in public hospitals, Dr Yeoh said: 'I worked in the bureaucracy and know how [to deal with it]. I won't bang my head against the wall ... People always blame the system. I believe there are ways to do better within the system.'