PITTSBURGH (AP) _ Foreign patients are coming to the United States for kidney transplants with ''relatives'' who are really strangers being paid to donate a kidney, according to a report published Monday.

The subterfuge is employed to circumvent U.S. laws against buying and selling of organs for transplant, The Pittsburgh Press said.

The newspaper said that kidneys are commonly sold in nations that allow the practice. People are born with two kidneys and can live with just one.

One Japanese man claims to coerce clients of his loan-sharking business to settle their debts by donating kidneys, the paper said.

The allegations emerged after the newspaper's 10-month investigation of ethical issues surrounding organ transplants and the shortage of available organs.

Transplant surgeon Dr. Hans Solinger of the University of Wisconsin Medical Center in Madison said he removed a kidney from a Bombay, India, man last January and transplanted it into another Bombay man. The two men said they were cousins.

Dr. Neeru Arora of Jaslok Hospital in Bombay said that after they returned, the recipient confessed he had purchased the other man's kidney.

''They didn't tell me that until they'd returned to India, of course, because they knew that if they had they wouldn't have got the transplant,'' the Press quoted her as saying. She said she bans paid donors from her program even though organ selling is legal in India.

Claiming to be cousins is a common way to disguise unrelated donors and recipients, the newspaper quoted surgeon Bhupendra Gandhi of Breach Candy Hospital in Bombay as saying.

''You don't need sophisticated tests to show these people aren't relatives. You can use your common sense,'' said Dr. Bernard Cohen, director of Eurotransplant, a network covering five European nations.

''If you had a parade of patients ... and virtually every donor they brought with them was a cousin, no aunts, no uncles, no parents, no siblings, ... wouldn't you be suspicious?'' he asked.

The newspaper quoted Haruo Sugiyama of Tokyo as saying he was a loan shark and organ broker who asks for a kidney when a borrower can't repay a loan as promised.

''I threaten them. I persuade them,'' Sugiyama was quoted as saying.

Sugiyama said most of his transplant clients have their operations performed in Japan.

Prison inmates in the Philippines have been donating kidneys since 1972 under a government program to encourage transplants, the newspaper said.

''The inmate's records are reviewed regularly for parole and the fact that a kidney is donated is, of course noted. This is an inducement, even though we have never stated it would lead to a more rapid parole,'' said Dr. Enrique Ona, chief of transplant surgery for the National Kidney Center of the Philippines.

If an organ sale ''helps a man's children go to school is that unethical? In a rich country like America you can say that shouldn't be the way, but that is the reality in the Third World,'' Ona said.