British surgeons today accused China of using organs from executed prisoners in its booming transplantation trade.

"It's important that people thinking of going for transplantation in China are fully aware there's a possibility that their donor organ may come from someone who has been executed," Professor Stephen Wigmore, the British Transplantation Society's head of ethics, told Guardian Unlimited.

On Monday, the World Organisation to Investigate the Persecution of Falun Gong released a report that claimed hospitals in China were racing to complete operations before tighter regulations come into force in July.

Another report by the same body last month claimed an "organ bank" of prisoners waiting to be executed for organ-harvesting existed in Shenyang, in Liaoning province.

Last December, China's deputy health minister, Huang Jiefu, made the first official admission that the country harvested organs from executed prisoners. He said regulations were needed to "standardise" the practice.

Amnesty International estimates China executed 3,400 people in 2004 and sentenced 6,000 to death. According to estimates in the state-run China Daily newspaper, up to 20,000 donor operations are performed in the country each year.

China claims all executed organ donors give their consent for the use of their organs, but human rights groups say strong taboos in Chinese culture about being buried with missing organs make it unlikely all donors are consenting.

New rules banning the sale of human organs from the start of July and requiring that donors provide their written consent were announced by Beijing last month.

However, Professor Wigmore said it was uncertain whether they would make much difference. The sale of organs is already officially illegal in China, although there is an extensive black market trade.

"We would welcome any reform of their system that improves the ethical aspects," the professor said. "It remains to be seen whether these regulations make any change."

Doctors in the UK have long been aware that a number of patients drop off transplant waiting lists each year, with many of them thought to have travelled overseas for operations.

Professor Wigmore said he had encountered two patients in the UK who had contemplated travelling to China for organ transplantation.

There are currently 6,689 people awaiting donations on the UK donor lists, with 13.1 million signed on to the register to donate their organs. Around 400 people each year die while waiting for transplant donors in the UK.

Organs only last a few hours once they have been removed from a body. Almost all donated organs in the UK are sourced in Britain, except for a small number shared via an EU pooling system.

The Shanghai-based China International Organ Transplant charges from $30,000 (£16m) for cornea transplants to $180,000 for liver-kidney transplants. It advertises maximum waiting times of one month for kidney transplants, compared with a median wait of two years in the UK.

Professor Wigmore said the short waiting times were an indication that people could be being executed "to order" for their organs.

Eric de Leon, an American who flew to Shanghai for a liver transplant last month, has written about the experience in his blog.

His wife wrote that the liver he received on 15 March was that of a "young and healthy" 20-year-old, but a posting rejected criticisms of the choice to get a transplant in China.

"Yes, they harvest organs from executed prisoners. No, they don't just go out and shoot a prisoner because a westerner, a Brit, an Israeli, a Malaysian, or anyone else for that fact, shows up with the need for a liver, kidney, lung or heart.

"The prisoners do in fact have to give their consent to donate."