A gang of alleged human organ traffickers has been detained in east China's Shandong Province, after police received a tip-off from a previous donor.

Officers apprehended the group in an unlicensed clinic in the provincial capital Jinan on Sunday night.

A 23-year-old donor had already received anesthetic and the would-be organ recipient was being prepared for transplant surgery next door, local newspaper Qilu Evening News reported.

Police have closed the private unlicensed clinic. Both the donor, from Jiamusi City in Heilongjiang Province, and the recipient, from Shaanxi Province, have been admitted to a local hospital.

Earlier this month, a previous donor, Wang Ming, 24, from Chongqing City in southwest China, told police a group was organizing human organ trafficking in Jinan.

Wang decided to inform on the gang after he said they treated him badly.

"I sold my kidney but received little reward," he said. "I even ended up with an infectious wound, but the traffickers refused to take responsibility and treat me."

Wang told the newspaper he made contact with the traffickers through the Internet. He was told to come to Jinan, where he and four other donors stayed in a shabby hotel.

Wang underwent transplant surgery on August 25. He said he was forced to accept a fee of 20,000 yuan (US$3,138) - much less than he had expected to receive.

The donor said he was forced to accept this because he was shown the paperwork detailing his fee just after he had been anesthetized and was on the operating table.

Wang told the newspaper that due to the effects of the anesthetic he was unable to utter a word and refuse. "I was so afraid that I decided not to go ahead with the operation, but I couldn't speak."

Wang's wound became infected and has still not healed, the newspaper said.

According to police, this is a well-organized underground group.

Earlier this month, it was reported that eight alleged traffickers from Shandong had been detained in north China's Hebei Province.

China has long banned human organ trafficking but high demand and low supplies have led to a black market.