WASHINGTON (AP) - The House Ethics Committee is launching a formal investigation into a Florida congressman who pleaded guilty to a misdemeanor cocaine possession charge last month. Ethics Committee Chairman Michael Conaway and ranking Democrat Linda Sanchez said in a joint statement Monday the committee voted unanimously to open an investigation into Rep. Henry "Trey" Radel (Ruh-del'), a freshman Republican who represents the Fort Myers-Naples area. Radel admitted to buying cocaine in October in Washington from what turned out to be an undercover federal agent. He is being treated at a drug rehabilitation center while on leave from Congress. A spokesman in his office said Radel expected an ethics investigation. Republican Rep. Charlie Dent of Pennsylvania chairs the investigation committee. New York Rep. Yvette Clark will be the panel's senior Democrat.