Mr. Rangel, who heads the House Ways and Means committee and who has served his Harlem district for nearly four decades, has been under investigation by two house subcommittees.
The guilty finding led to quick condemnation from Republicans, who have made the powerful congressman a frequent target.
“Once promised to be the ‘most ethical Congress in history,’ the Democratic majority now has a serious ethics scandal on its hands thanks in-part to House Speaker Nancy Pelosi,” said Ken Spain, a spokesman for the National Republican Congressional Committee. “For months, and even years, Nancy Pelosi has been promoting corrupt actors within her caucus ranks when she should have been punishing them.”
One of the two House panels began looking into Mr. Rangel after The New York Times reported that he was renting four rent-stabilized apartments in Harlem at a price that was well below market value, despite rules forbidding House members from accepting gifts worth more than $50.
The inquiry — which also included an investigation into whether he improperly used his office to raise money for an academic center named for him — later expanded after questions were raised about unreported taxable income Mr. Rangel received from a villa he owns in the Dominican Republic.
At the same time, a second subcommittee was investigating a complaint from an ethics advocacy group that accused Mr. Rangel and four other members of Congress of violating restriction on accepting travel from donors who employ lobbyists by attending a conference last November in St. Maarten. The conference was sponsored by Citigroup, but Mr. Rangel reported in an amended disclosure form that his trip was paid for by the Carib News Foundation, which had underwritten his travels in the past.
It was that inquiry that resulted in the guilty finding by the House committee.