The investigators are examining the relationships between seven members and an influential lobbying firm founded by a former Capitol Hill aide.

The investigations by two separate ethics offices include an examination of the powerful subcommittee chairman, John Murtha, D-Pa., as well as others who helped the PMA Group secure earmarks for clients. The lawmakers received campaign contributions from the firm and its clients.

Records obtained by The Washington Post show that the members also under scrutiny are Peter Visclosky, D-Ind., James P. Moran Jr., D-Va., Norm Dicks, D-Wash., Marcy Kaptur, D-Toledo, C.W. Bill Young, R-Fla., and Todd Tiahrt, R-Kan.

The records also indicate that the House ethics committee staff recently interviewed the staff of Rep. Devin Nunes, R-Calif., about the lawmaker's allegation that a PMA lobbyist threatened him in 2007 when he resisted steering federal funds to a PMA client. The lobbyist told a Nunes staffer that if the lawmaker didn't help, the defense contractor would move out of Nunes' district and take dozens of jobs with him.

The document obtained by The Post offers the most-detailed picture yet of a widening inquiry into the relationships between members and PMA, a lobbying firm founded by Paul Magliochetti that has been under criminal investigation by the Justice Department. A year ago, the FBI raided PMA's offices.

The document shows that both the ethics committee and the Office of Congressional Ethics are looking into the matter. The OCE investigates and makes recommendations to the House ethics committee, which has the power to subpoena and sanction members.

Together, the seven members have steered more than $200 million in earmarks to clients of the PMA Group in the past two years, and received more than $6.2 million in campaign contributions from PMA and its clients in the past decade, according to an analysis by Congressional Quarterly and Taxpayers for Common Sense.

The OCE has interviewed some of the lawmakers, including Kaptur last week and Moran a few weeks ago. It has invited others in for interviews, such as Visclosky, and posed numerous questions to the members' staffs.

Several Hill staffers said they are confused by what appears to be a dual track, with both the OCE and the ethics committee pursuing similar questions.

Kaptur's spokesman said her office does not understand the duplication but will answer all questions.

"The congresswoman has always emphasized openness and transparency, and it almost goes without saying she will continue to cooperate with the OCE and, if it goes to the Committee on Standards, with that committee as well," said Kaptur spokesman Steve Fought. "She has nothing to hide."

Murtha's office declined to comment. The offices of Dicks, Visclosky, Young and Tiahrt did not respond.