Authorities are investigating whether Rep. Tim Murphy's legislative staff members performed campaign work while on government time, which would violate federal law, according to a broadcast report.

Federal authorities have started interviewing Mr. Murphy's former staff members, according to KDKA-TV, which cited anonymous sources.

Mark Carpenter, Murphy's press secretary, declined to comment on the report of a federal investigation, but acknowledged that the lawmaker had forwarded similar allegations to the House ethics committee for review.

Mr. Murphy "welcomes a robust review of all claims," Mr. Carpenter said. Bill Crowley, special agent for the FBI in Pittsburgh, would not say whether an investigation is under way. Bob Cessar, a spokesman with the U.S. attorney's office in Pittsburgh, declined to comment.

Mr. Murphy, R-Upper St. Clair, won a third term Nov. 7.