MUMBAI, India, Jan 28, 2008  -- An illegal kidney transplant racket in which hundreds of India's poor were forced into having their kidneys removed has been uncovered by police.

The mastermind behind the scam is believed to be Dr. Amit Kumar (also known as Dr. Santosh Raut) who Mumbai police have been chasing since 1993, according to the Indian Express newspaper, a local Indian newspaper. The doctor was also arrested in Delhi in 2000.

Officials said that 500 to 600 kidneys were stolen or purchased from victims in Gurgaon, a high-tech city on the outskirts of New Delhi, . The kidneys were transplanted into the bodies of wealthy Indians or foreigners. Five foreign tourists, including two Americans, were found in what police described as a "luxury guest house" owned by the doctor on Saturday. There was a waiting list of some 40 foreigners from at least five countries.

The investigation is ongoing and police are raiding hospitals' offices and guest houses, Gurgaon Police Commissioner Mohinder Lal told reporters in Gurgaon on Monday.

Unsuspecting victims of the scam said they were promised a job, then taken to a private house and forced at gunpoint to sell their kidneys. The transplants occurred inside the house, which had a hidden state-of-the-art operating room inside. Those who sold their kidneys received about 50,000 rupees or $1,800 - although wealthy clients paid ten times that amount.

Many victims were told that they needed to undergo a blood test screening for a potential job– only to wake up to find they had undergone surgery and had their kidneys extracted.

"I was approached by a stranger for a job. When I accepted, I was taken to a room with gunmen," Mohammed Salim told India's local NDTV television channel. "They tested my blood, gave me an injection and I lost consciousness. When I woke up, I had pain in my lower abdomen and I was told that my kidney had been removed."

Suspicious neighbors said they had noticed blood running out of the house's gutters, as well as blood-soaked bandages and even bits of flesh thrown into an open plot near the house, according to Reuters.

The doctor accused of heading the group may have fled the country and as many as 50 medical officials may have been involved in the racket, according to police.