Federal prosecutors are investigating allegations that more than $70,000 was paid fraudulently to ghost employes listed on the payroll of American Samoa's nonvoting delegate in the House, sources said.

Investigators are studying allegations that Del. Fofo I.F. Sunia (D) and his chief aide, Matthew K. Iuli, arranged for paychecks to be issued to Samoans falsely listed as working in Sunia's district office in the U.S. territory in the Pacific, said the sources, who spoke on condition of anonymity.

Among those listed on the payroll records kept by the House are a Samoan politician and the operator of a Samoan travel agency.

Secret Service agents have traveled twice to American Samoa in recent months to investigate the alleged payroll fraud. The Secret Service has jurisdiction to investigate the cashing of government checks under false pretenses. No criminal charges have been brought.

Sunia, 50, has contended to prosecutors that Iuli, his administrative assistant, was the "mechanic" who implemented the scheme, according to one source.

Sunia has been quoted in the Samoan News, a twice-weekly newspaper published in Pago Pago, as acknowledging that he is under investigation. But Sunia declined to specify the nature of the investigation.

On Thursday, he said, "I've retained a counsel to look into the matter. I have been advised not to discuss the question."

Sunia has retained Earl J. Silbert, a prominent defense lawyer and a former U.S. attorney here, as his lawyer. Cary M. Feldman, an attorney in Silbert's firm, declined to comment.

Richard Salsman, Iuli's attorney, declined comment on any aspect of the investigation.

Sunia has represented American Samoa in the House since 1981. As a delegate, Sunia may cast votes in House committees but not on the floor.