He would spend between two days and two weeks making original moulds for mass-produced Disney plastic toys, working from photographs of characters from films such as Pirates of the Caribbean or Beauty and the Beast.

Before leaving the factory last February and launching their case against the Shenzhen factory for a total of about 700,000 yuan, Mr Huang and his colleagues claim they worked up to 347 hours a month even though the legal maximum under Chinese labour law is 40 hours a week plus 36 hours overtime per month.

One of them, 30-year-old Mr Chen - an art college graduate from Fujian province who worked at Haowei for five years before quitting in February - showed a factory work log recording how in December 2006 he would start at 8am and finish as late as midnight every day. He worked seven days a week with only Saturday evenings off, clocking up 269.5 hours and another 77.5 hours of overtime.

Including overtime, they earned up to 3,300 yuan a month - three times what production line workers in the factory could earn - but say they were worked so hard at illegally low rates of pay and overtime that they decided to quit and sue for compensation. Hundreds more lower-paid workers went on strike to protest against pay and conditions in September.

'When I first did this job I was excited and proud of what I was doing,' Mr Chen said. 'As a Chinese worker, I know I will never have the opportunity to travel by plane - but the toys that I made did. They went to children all over the world and that used to make me happy.'

The sculptors took their case to the Labour Bureau and were initially offered two months' compensation. They rejected the offer and, weeks after September's worker unrest, won a ruling in the district-level court that they were entitled to a reassessment of their compensation. They are still waiting for a settlement.

For Mr Chen, it is much more than a matter of money. 'People should boycott Disney toys,' he said. 'As workers, we would never buy Disney toys for our children because we know they are made at such an extreme cost to workers.

'We hope that by making our case known overseas, Disney can be made to strengthen its labour monitoring mechanism and check that these factories obey labour legislation.'

Mr Huang said: 'We know Disney has certain principles. It says its contractors should obey the local labour laws and safeguard labour rights and the health of workers. Those laws haven't been obeyed but Disney continues to give orders to Haowei. When we decided to launch a legal case against the company, my former employers told me, 'It's no use because we have good relations with the government and Disney. You won't stop us getting orders from Disney. It is only you who will suffer'.'

Workers say that since the September strike, overtime pay and conditions have improved at Haowei, which employed more than 1,000 workers but has since reduced its workforce as it prepares to move to a new site in Dongguan . However, Hong Kong-based pressure group Students and Scholars Against Corporate Misbehaviour (SACOM) says the amount of money deducted from workers' pay packets for accommodation and food has been simultaneously increased, leaving workers little better off.

Haowei is not the only Disney-contracted factory in the area to attract claims of underpay and poor working conditions. Workers reported similar abuses of labour laws in the Yonglida toy factory in Dongguan which employs about 1,000 workers and makes Disney-brand soft toys, even though its authorisation to produce the toys has been revoked. Mr Meng, 23, from Guangxi province, who works in the packaging department, said he worked from 7.30am until as late as 2am, with no overtime pay.

'There are no set hours. There is just a quota to meet every day. When we finish our quotas every day we can leave. Sometimes it takes until midnight. Sometimes, in the peak months [between April and September] it takes until 2am.

'My quota [for removing dirt and fluff from soft toys] at the moment is 4,000 toys a day but during the peak months it is sometimes raised to as much as 6,000 a day.'

Workers interviewed at Yonglida said they were given only one day off a month and paid between 700 and 1,000 yuan a month, depending on how many times they met or exceeded their quota.

Production line worker Mr Luo, 30, said: 'The bosses are very harsh with the workers. If you say you are tired and don't want to work late, the manager will immediately say, 'You are fired. Please go'. If you refuse to go they will get the security guards to remove you.

'Two days ago, a colleague of mine was beaten up by the manager. He didn't obey the manager's orders so he was punched. He was hurt badly and was so terrified he didn't come back to work and didn't collect the salary he was owed. That kind of thing happens a lot.'

Workers interviewed claimed that new recruits at Yonglida were not paid their first month's salary until they had been at the factory for two months and 10 days - meaning they were always owed 40 days' pay, which they would forfeit if they resigned, making them less likely to walk out on the job.

'When officials check the factory, they never talk to the workers, only the bosses,' Mr Luo said. 'They are shown false lists of workers' salaries which we have to sign. The list will show that a worker earns 1,200 yuan when he really earns only 800 yuan.'

SACOM last weekend sent a letter to Disney chief executive officer Roger Iger demanding that the company ensures that the mainland factories it uses follow the labour laws.

The letter called on Disney to enforce its international code of conduct at factories in southern China, to give every Chinese worker a copy of the code of conduct in Chinese and to disclose a full list of outsourcing suppliers in the way that Nike did after similar pressure over labour issues in its Asian factories.

A senior official at the Haowei factory, who declined to be named, admitted in a telephone interview there was 'a lot of room for improvement' in labour conditions but said the factory was working with Disney to provide better conditions.

Referring to the case brought by the five workers, he said: 'We are still contesting the case. The five people have their reasons. We have our reasons. The court is investigating the issue and hasn't yet made a judgment. It's not appropriate to say if we are at fault or if they are at fault.

'These men ... had to work a lot of overtime because the whole factory production line was waiting for those moulds. When they finished, they had free time.

'We admit that working conditions at Haowei were not good. It's not all our fault because the building is old and it is in poor condition ... We are now moving to a new site in Dongguan which will provide much better conditions.

'We have been working for Disney for more than 10 years. Disney has sent a lot of people to our company and they have helped us train workers to improve the quality of our products and they have made a lot of suggestions about how to improve working conditions. We do our best to make Disney happy.'

A Yonglida spokesman said the factory had 'taken steps to review and improve our workers' remuneration and benefits with a view to complying with the Chinese labour laws'.

A Disney spokesman said violations of labour laws had been identified by Disney inspectors at Haowei in June and 'corrective action' had been taken. 'We believe that the efforts made so far together with the continued commitment of the licensee ... will lead to long-term sustainable compliance at the factory following its relocation to a new site.'

A Disney report on conditions at Haowei in November concluded there was 'positive worker sentiment' because of 'improvements in wages and working hours'.

Yonglida, on the other hand, appeared to be producing Disney merchandise without proper authorisation, the spokesman said. Although it received Disney's permission to produce brand-name goods in 2004, authorisation had been subsequently revoked by the regional licensee that directly awards contracts to manufacturers.

'Disney staff have been prevented from entering and inspecting this factory and have not been able to verify the allegations that have been made,' the spokesman said. 'We continue to investigate and are working with industry contacts to verify claims made.'

For the toymakers fighting back over their treatment, meanwhile, the experience has had a profound impact. 'I felt like a machine while I was in that factory,' Mr Chen said.

'I lost my passion for the work I did and I lost my passion for life. Now I just want to help people caught in the same situation I was in.'