Few moral qualms to the research appear to exist on the mainland, however, where the government has provided generous funding for the sector. Last year, the team of stem cell scientists dispatched by the British government's Trade and Industry Department visited the mainland as part of a field trip which included Singapore and South Korea. They were impressed with the quality of research on the mainland.

'Stem cell science in China is booming,' they said in a report released late last month. 'They are at, or approaching, the forefront of international stem cell research.' Such praise is all the more impressive from British scientists who are considered leaders in the field after the first animal, known as Dolly the sheep, was cloned in Scotland in 1997.

The report said Chinese laboratories matched and even exceeded those of British research centres. 'These facilities were, in every case we saw, equipped, funded and staffed to levels at least as good - in most cases better - than equivalent centres in the UK,' the team said.

Some of the mainland's greatest strides in stem cell research have been made by Professor Zhu Jianhong of Huashan Hospital at Fudan University, which houses China's largest neurosurgery department. Professor Zhu's work is not for the squeamish - he has replicated human brain cells after taking tissue from patients with open head wounds.

Only tissue that is found outside the skull because of an injury is used for replication in the lab - no tissue is removed from inside the skull. Replication usually lasts one to two months before the cells are transplanted into the brain.

The first patient to undergo this treatment had a chopstick lodged in the brain. The British report said that after the cells were transplanted into the brain, the patient recovered the ability to walk over a 12-month period.

A further eight cases have been tried by Professor Zhu, with matching controls, where surgery without the transplant of cells takes place. 'Significant efficacy has been observed, although Professor Zhu remains cautious, observing that the degree of spontaneous recovery is highly variable in these cases,' the report said of the eight cases.

Professor Sheng Huizhen, of Xinhua Hospital in Shanghai, came to the world's attention in 2003 for transferring the nuclei of adult human cells into rabbit eggs that had been emptied of their genetic material. Professor Sheng's team claimed the hybrid was a source of human embryonic stem cells which could then be grown into a wide variety of tissues.

Professor Alex Zhang Yu, of Beijing's Xuan Wu Hospital, is researching with animals how to use stem cells as possible therapies for diabetes and neurodegenerative disorders such as Parkinson's disease.

Professor Zhang's lab has an extensive primate centre in southern China, with about 6,000 monkeys available for research from a colony exceeding 30,000, according to the report. Given the pressure against animal testing in some western countries, the British authors believe Professor Zhang's centre may prove useful for collaboration with western universities.

A few American universities, including Stanford, are discussing possible co-operation over transplantation studies in monkeys. 'This is potentially an area where foreign laboratories might wish to enter into agreements, given the approach to animal experimentation in China and the size of this primate colony,' the report said. 'However, the mission did not evaluate the quality of the research facilities.'

In addition to treating human conditions, some mainland stem cell research focuses on animal cloning. Professor Zhou Qi of the Chinese Academy of Medical Sciences in Beijing, in collaboration with a French laboratory and a bio-tech company, has already cloned the first rat and hopes to eventually replicate pandas, which are in danger of becoming extinct.

Universities have also set up companies to explore possible business opportunities from stem cell research.

SinoCells is a company set up by scientists from Beijing University which, among other areas, is looking at how to preserve stem cells. The firm is also using stem cells to better understand how Chinese herbal medicines work and experimenting with ways of transplanting specially treated stem cells grown in the laboratory into the eye to treat corneal disease. 'This has been tried in three patients with encouraging results,' the report said. 'Their expectation is two to three years for pre-clinical work and a further two years for taking these cells [for use in] the clinic.'

StemGene - which raised US$30 million listing on the Shanghai Stock Exchange - is researching how to better utilise stem cells taken from the blood of umbilical cords. While this blood is a relatively convenient source of stem cells used to treat certain immune disorders and blood malignancies, one cord only provides enough to treat a small child, according to the report. Hence, StemGene is researching how to best expand stem cells from cord blood to enable more treatment of adults.

StemGene has been granted a licence by the central government to establish a cord blood bank in Tianjin, Hebei province. Customers who have their cord blood stored by StemGene, at a cost of about US$3,000, receive free health insurance for their first 22 years. The insurance policy covers any stem-cell-therapy-based procedure and the associated hospital fees, including outpatient treatment.

The mainland's strides in stem cell research are partly due to fewer moral concerns than some western countries. 'There are seemingly fewer moral objections to the use of embryonic stem cells,' the report said.

'Where stem cell research in China is unique in our experience is in the drive in the clinics. There is much less resistance than would be met in the west to pursuing experimental therapies into clinical practice.'

But is the sensitive area of stem cell research well regulated ion the mainland? 'It is evident that the Chinese authorities are anxious to establish a regulatory and ethical framework in relation to human embryonic and foetal stem cells that reflects emerging international standards,' the report authors concluded.

Yet they warned in the same conclusion that they were unsure how effective regulation was in stem cell research centres outside the top institutes they visited.

'It was not possible in the course of such a short mission to determine how fully such standards are accepted and reflected in practice outside the centres of international excellence,' the report said.

Although not highlighted in the report's conclusions, the main text also contains grounds for concern. Regulation of clinical trials was described as 'patchy' in the past by some Chinese doctors, despite approval being required from the central and provincial governments and the universities' or hospitals' ethics committees.

However, these doctors said the regulations had improved recently and the report noted that 'many of the research teams... were well aware of the ethical issues raised'.

As in other countries, under Chinese rules governing stem cell science donor consent is required for embryos to be used for research. Embryos are often taken from surplus ones produced in IVF clinics, aborted foetuses and umbilical cords. 'We were unfortunately unable to access any copies of the consent forms used in the IVF clinics,' the report said.

'With regard to foetal tissue, we were assured that parental consent was required. Similarly, parental consent was required in relation to cord blood, but again we were not able to access the consent forms.'

However, the visiting team of doctors viewed the consent forms at Huashan Hospital for operations where patients had been implanted with their own cultured brain cells.

The authors - who also visited Singapore and South Korea - found scientists receptive to the idea of collaborating with their British counterparts on future projects.

'Each of the three countries visited confirmed strong interest in the opportunity for collaborative interaction with UK-based academic and commercial organisations,' the report said.