WASHINGTON — The FBI is investigating whether Rep. Curt Weldon, a Republican of Pennsylvania, used his influence to secure lobbying and consulting contracts for his daughter, two people familiar with the inquiry said Saturday.

The inquiry focuses on lobbying contracts worth $1 million that Mr. Weldon’s daughter, Karen Weldon, obtained from foreign clients and whether they were assisted by the congressman, they said. They spoke on condition of anonymity because of the confidentiality of the criminal investigation.

Mr. Weldon, a 10-term Republican from the Philadelphia suburbs, long has denied any wrongdoing, and his top aide said Saturday no one had notified him of an investigation.

“I think if there was an investigation, somebody would have contacted us,” Mr. Weldon’s chief of staff, Russ Caso, said.

Mr. Caso said Mr. Weldon and his staff were “100% caught off guard” when they learned of the investigation, first reported late Friday by McClatchy Newspapers. This account cited two individuals with specific knowledge of the existence of the investigation; they declined to be identified because of the confidentiality of criminal investigations.

Mr. Caso, whose boss is in a tight race for re-election on November 7 against Democrat Joe Sestak, tried to cast doubt on reports of the investigation. “Unidentified sources mean nothing,” Mr. Caso said. “There’s no substance in that story. It’s a flimsy story.”

Two people familiar with the investigation told the AP on Saturday that the inquiry was being handled by agents from the FBI’s field offices in Washington and Philadelphia and was being coordinated by the Justice Department’s Public Integrity Section. Spokesmen for the Justice Department and the FBI declined comment Saturday.

Those two people familiar with the investigation confirmed that federal agents were examining Mr. Weldon’s work between 2002 and 2004 to help two Russian companies and two Serbian brothers connected to President Milosevic of Yugoslavia. They had hired Solutions North America Inc., a company operated by Karen Weldon and Charles Sexton, a Republican ally of the congressman.

Vice chairman of the House Armed Services committee, Mr. Weldon is a Russian speaker regarded by some as a foreign-policy expert who has clashed at times with the Bush administration.

Over the last few days, the Democratic Congressional Campaign Committee has mailed fliers to voters in Mr. Weldon’s district accusing Karen Weldon of getting help from her father on lobbying projects.

Michael Puppio, Mr. Weldon’s campaign manager, questioned the timing of the mailing and published reports about the investigation. He accused Democrats of “attempting to smear the congressman and his entire family” in the final weeks of the campaign.

A spokeswoman for the DCCC, Jen Psaki, said it’s “bizarre, paranoid, and absurd” for the Weldon campaign to imply there’s a link in the timing of the mailing and the published reports.

The Weldon investigation comes at a critical time for Republicans who are fighting to maintain a majority in the House of Representatives in a midst of scandals.

On Friday, Rep. Bob Ney, a Republican of Ohio, pleaded guilty in the Jack Abramoff lobbying scandal, which has touched on federal lawmakers, former aides and members of the Bush administration.

At the same time, an inquiry is under way on Capitol Hill into whether Republican House leaders or their top aides covered up questionable behavior of Rep. Mark Foley toward teenage males who worked as House pages.