By Sanjoy Majumder
BBC News, Delhi
Police in India have issued an alert for a doctor alleged to be involved in an organ trading racket.
Many outstation labourers come to Gurgaon for work
Last week, police in Gurgaon, a suburb of the capital Delhi, raided a house which was used to carry out illegal kidney transplants.
Hundreds of poor labourers were tricked into selling kidneys, officials says.
Trade in human organs is banned in India but many continue to sell their kidneys to clients, including Westerners, waiting for transplants.
Gurgaon is an affluent suburb of Delhi, home to high-rise apartment blocks and call centres.
It is here, in a nondescript house, that many poor labourers were lured from across northern India and bribed into selling their kidneys, according to the police.
For this they were allegedly paid up to $2,500.
The clients are said to be wealthy Indians, and even some foreign visitors, who were in urgent need of a kidney transplant and willing to pay large sums for it.
Last week, the police raided the illegal clinic after being tipped-off by a victim.
Four people were arrested but the main person alleged to be behind the racket, a doctor, is missing.
Gurgaon police commissioner Mohinder Lal told the BBC that an alert had been sounded at airports to prevent him from leaving the country.
He said police also planned to approach Interpol to issue a warrant for his arrest.
Despite banning the trade in human organs India continues to be one of the major centres of the trade.