Three members of an organ-trafficking syndicate have been arrested and doctors at a government hospital questioned by police after Al Jazeera uncovered an illegal organ-trading operation.

People from a village in West Java, which has a population of 30, sold their kidneys for around $5,000, the exclusive investigation revealed.

Police said that they had questioned six doctors so far for possible collusion with organised criminals in the trade.

"I was in a really bad situation. I had huge debts and didn't have a house ... I couldn't pay my rent for four months," one of the kidney sellers, Edi Midun, told Al Jazeera.

Selling organs is illegal in Indonesia, but people can donate them to friends and relatives.

To sell his kidney, 39-year-old Midun had to pretend that he knew the recipient of his kidney well, acting as a donor. A middleman changed his age to 25 to increase his chances of being accepted.

Further investigation needed

A government hospital accused of helping the traffickers has denied any involvement, but its director says the screening process is designed to weed out any cases of organ trading.

"If we find the [organ trading] syndicate works together with the hospital, of course the doctors will be prosecuted," Arie Dharmanto, a police investigator, told Al Jazeera.

"We need to look at the issue case-to-case. This needs to be further investigated. If there are possible mistakes - which could be the case - then this should be part of the investigation," Czersna Soejono, the director of the Cipto Mangunkusumo Hospital, said.

According to Indonesia's health ministry, 150,000 Indonesian kidney patients need a transplant.

In an effort to stop the kidney trade, MPs have urged the government to establish a donor bank, where organ donation will be regulated and donors properly screened.