"I was just trying to help the patients. A relative of one of my clients went down on his knees when asking me to help find a kidney for his wife," said Cai Shaohua in sobs at the Haidian district court on Wednesday. Cai is a criminal suspect of illegal human organ trading.

The court opened a session on Wednesday in the trial of two organ agents. The prosecutor accused the two suspects of conducting illegal businesses and counterfeiting official seals and documents.

Cai Shaohua and Cai Shaoxia, the suspects, who are originally from Dancheng, Henan province, are brothers. Prosecutors alleged that they brokered four kidney transplants and altogether charged 584,000 yuan (US$85,000) from the organ recipients.

They earned 95,000 yuan in net profits after paying the donors, hospitals and other agents. The four deals were made between March and May 2009 in Beijing, according to the prosecutor.

The elder brother, Cai Shaohua, who was arrested on May 28 last year, is accused of being the principal offender, while Cai Shaoxia, who was persuaded by his brother to join the "business" last year, assisted him by taking care of the donors and forging the documents.

One of the organ recipients was Wang Dexin, who suffered from uremia for years. Cai Shaohua found her a donor, Zhao Jinquan, who matched Wang's blood type and was willing to sell a kidney.

Zhao, a peasant from Hebei province, owed more than 70,000 yuan in loans he took out to build a house, and was eager to pay back the debt. He contacted an organ agent called Xiao Qiang, who introduced him to Cai Shaohua.

Cai Shaohua forged an ID card and other official documents for Zhao, and let him assume the identity of Wang's son by using the name of "Ma Le".

The operation was on May 26 last year at Chaoyang Hospital. Afterwards, Wang paid 135,000 yuan to Cai. Cai earned a profit of more than 20,000 yuan after paying the donor, the hospital and the agent, who introduced the donor to him. Zhao received 40,000 yuan.

Commercial trading in human organs is strictly banned in China. Only a patient's spouse, immediate relatives and relatives within three generations are allowed to donate organs to the patient.

The supply of human organs, however, lags far behind demand. Some 1.5 million patients need organ transplants every year, but only 10,000 patients are able to receive donated organs.

The prodigious gap has prompted some people to broker illegal organ deals between recipients and donors.

Although Cai Shaohua admitted that he had committed the crime, he insisted that his intention was to help the patients.

"Both the recipients and donors did it willingly and my job was just to introduce them to each other," he told China Daily after the trial.

Hu Yihua, the defending counsel of Cai Shaohua, said the defendant had little malicious intent and that relatives of some patients who "bought" organs from Cai even expressed gratitude to him.

The court did not make any judgment on Wednesday. The verdict will be declared later.