WASHINGTON  The Republican who will head the House committee that oversees domestic security is planning to open a Congressional inquiry into what he calls “the radicalization” of the Muslim community when his party takes over the House next year.

Representative Peter T. King of New York, who will become the chairman of the House Homeland Security Committee, said he was responding to what he has described as frequent concerns raised by law enforcement officials that Muslim leaders have been uncooperative in terror investigations.

He cited the case of Najibullah Zazi, an Afghan man and a legal resident of the United States, who was arrested last year for plotting to bomb the New York subway system. Mr. King said that Ahmad Wais Afzali, an imam in Queens who had been a police informant, had warned Mr. Zazi before his arrest that he was the target of a terror investigation.

“When I meet with law enforcement, they are constantly telling me how little cooperation they get from Muslim leaders,” Mr. King said.