A Chinese health official has vowed executed inmates will no longer be the main source of organs for transplants in three to five years, as the country sets up a donation system, state media said.

China has long vowed to reduce its reliance on death-row inmates for organs, but high demand and a chronic shortage of donations mean they have remained a key source -- a situation that has generated heated controversy.

But Huang Jiefu, vice health minister, said the government wanted to abolish this practice altogether and was in the process of setting up a nationwide organ donation system, the official Xinhua news agency reported.

"China... promises that within three to five years, it will completely change the abnormal method of relying mainly on death row inmates to obtain transplant organs," Huang was quoted as saying in the report late Thursday.

The health ministry would not confirm his comments when contacted by AFP.

Beijing banned the trade in human organs in 2007 and two years later began rolling out a nationwide donation system, which Huang said was currently being trialled in 16 provinces and cities.

But demand for organ transplants still far exceeds supply in the country of 1.3 billion people.

An estimated 1.5 million people need transplants every year, but only around 10,000 are carried out, the report said, citing health ministry statistics, opening the door to the illegal sale of organs and forced donations.

Organ donations are not widespread in China, where many people believe they will be reincarnated after death and therefore feel the need to keep a complete body.

International human rights groups have long accused China of harvesting organs from executed prisoners for transplant without the consent of the prisoner or their family -- charges the government has denied.

In 2009, Huang said the rights of death-row inmates were respected and written consent from prisoners was required before their organs could be harvested, state media said at the time.

Nonetheless, he has repeatedly conceded that executed prisoners are not a proper source for organ transplants.