China has said it will ban the sale of human organs from July in an attempt to clean up its transplant industry.
China says it will revoke hospital licences if transplant patients die
New regulations published by the health ministry require donors to give written permission and say transplants should be done only in specialist hospitals.
The move follows the deaths of several foreigners who travelled to China for transplants.
Correspondents say the measures fail to address a severe organ shortage which has spawned a lucrative black market.
It is estimated at least two million people in China need transplants each year but only up to 20,000 can be conducted because of the lack of organs, according to Chinese state news agency Xinhua.
Voluntary donations fall far below the level of demand because of cultural biases against organ removal before burial.
Human rights groups allege that many organs come from executed prisoners, including from those who may not have given their permission.
China's foreign ministry admitted on Tuesday that organs from prisoners were used - but said it was only in "a very few cases" and with the express permission of the convict, the Associated Press news agency reported.
"It is a complete fabrication, a lie or slander to say that China forcibly takes organs from the people given the death penalty for the purpose of transplanting them," said foreign ministry spokesman Qin Gang.
Critics have accused China's transplant business of being driven by profit rather than medical concerns.
Japan said earlier this year that it would investigate the cases of at least eight Japanese patients who fell ill or died after receiving organ transplants in China.
China's health ministry said the temporary ban on the sale and purchase of organs was being brought in to protect patients' health.
Under the new regulations, hospitals can have their licence to carry out transplants revoked if patients do not survive a certain number of years after the operation.
Transplant cases must also be discussed by an ethics committee and the legitimacy of the organ confirmed before the procedure can take place.