Two men are in jail on contempt charges for refusing to testify before a grand jury that is investigating fund-raising in the United States by the militant Islamic group Hamas.

Abdelhaleem Ashqar told The New York Times he refused to answer questions about several Palestinian advocates in the United States and abroad, the newspaper reported Saturday. He said he has been on a hunger strike since he was jailed Feb. 23 and has lost 25 pounds.One of those advocates is Mousa Mohammed Abu Marzook, the Hamas political leader who was jailed in New York during a bitter extradition battle with Israel until he was released to Jordan last year.

The second man jailed is Ismail Elbarasse. He allegedly shared an American checking account with Abu Marzook from which a contribution of several hundred thousand dollars was made to Palestinian groups abroad, said his lawyer, Stanley Cohen.