The search for the vendor was disclosed yesterday by Assistant U.S. Attorney John Curran during a bail hearing in U.S. District Court in Brooklyn. The hearing was for Ronald Mallay, arrested earlier this month on charges of being part of a plot to kill immigrants to collect their life insurance benefits.

Richard James, an insurance agent and well-known cable TV personality among Guyanese in the city, also was arrested in the case, in June.

Mallay, for his part, has been accused in a federal criminal complaint of involvement in two murders with James to collect hundreds of thousands of dollars in insurance - one in Queens in January 1998 and another in Port Mourant, Guyana, in June 1999.

Yesterday, Curran told Magistrate-Judge Lois Bloom that investigators are looking into a third suspicious death some years ago. He did not elaborate. Officials have indicated that a total of 21 unusual deaths have been flagged by an insurance company, and eight of them are under federal investigation, prosecutors have indicated.

Regarding the man identified in records as a flea market vendor, Curran told the judge that the insurance papers in his name were found in the home of Mallay's wife. The vendor was not identified.

Curran said the man still may be alive since there has been no request for payment on the insurance. However, the person was using a Social Security number linked to other people in addition to him, Curran said.

Mallay's bid for bail was denied by Bloom, who ruled that $650,000 in real estate equity offered as security by his relatives was inadequate.

The judge offered Mallay a chance to renew his bail application if he can offer enough property to secure at least a $1-million bond.

In a letter to the court, Curran had written that Mallay's lack of a job, an earlier federal prison sentence and his ties to his native Guyana made him a risk to flee before trial.

"Furthermore, in light of the continuing and serious nature of the charges, the defendant poses a danger to the community," Curran's letter read.