TORONTO - The alleged mastermind of an illegal kidney transplant ring has family ties to Canada and may have fled to this country, the lead investigator said Friday.

Speaking from his office in Gurgaon, India, Police Commissioner Mohinder Lal said Amit Kumar is the primary suspect in the ring and that Canadian authorities are being asked to assist in the investigation.

"His wife and two sons are in Canada,'' Lal told the Canadian Press in a telephone interview. "He could be there.''

He said he did not know where in Canada Kumar's family is living.

Interpol in Ottawa confirmed Friday they are "a point of contact'' in the investigation and are providing assistance to the Indian authorities. They declined to provide further details.

Kumar, 40, became the subject of an international manhunt late Thursday after Interpol issued a red notice for his arrest. A second notice, posted on the international policing agency's website, calls for the arrest of 36-year-old Jeevan Rawat.

Both doctors are wanted in India on counts of "illegal transplanting of kidneys, cheating and criminal conspiracy.''

Kumar is alleged to be the mastermind behind an elaborate organ harvesting ring based in Gurgaon, an affluent suburb of New Delhi.

Lal alleged kidneys were forcibly removed from as many as 500 people and then used to provide transplants for foreigners.

Lal said there is no evidence to suggest any of the recipients hailed from Canada, but said the investigation is ongoing.

He said police have identified recipients from the United States and a variety of European countries.

The ring was discovered after police raids on a number of hospitals and guest houses unearthed sophisticated surgical equipment concealed in residential neighbourhoods.

Police also allege potential donors were assessed using blood-testing machines installed in luxury cars. Several arrests have already been made in the case.

The Associated Press reported that while some donors willingly sold their kidneys for as much as $2,250, many were lured to operation sites, held at gunpoint and ultimately forced to undergo the procedure.

Mohammed Salim, who was rescued during a police raid, said he was promised paid construction work, as well as food and lodging, but found himself held prisoner in a house where his kidney was removed against his will.

"I don't know how I will survive,'' Salim told The Associated Press from a hospital bed. "I am the only earner in the family and the doctors said I can't do heavy work.''

There long have been reports of poor Indians illegally selling kidneys, but the transplant racket in Gurgaon is one of the most extensive to come to light -- and the first with an element of so-called medical tourism.

The low cost of medical care in India has made it a popular destination for foreigners in need of everything from tummy tucks to heart surgery.