WASHINGTON — Rep. Michele Bachmann and her short-lived campaign last year for the GOP presidential nomination are being investigated by the Office of Congressional Ethics.

A lawyer for the Minnesota Republican said Monday that Bachmann is cooperating with the investigation. The Office of Congressional Ethics is an independent investigative body established by the House five years ago to conduct preliminary investigations into allegations of misconduct by House members or their aides. The panel can dismiss cases or refer them to the House Ethics Committee.

“There are no allegations that the congresswoman engaged in any wrongdoing,” lawyer William McGinley, of Patton Boggs said. “We are constructively engaged with the OCE and are confident that at the end of their review the OCE Board will conclude that Congresswoman Bachmann did not do anything inappropriate.”

The Daily Beast first reported Monday that Bachmann was the subject of an OCE investigation of financial transactions by her presidential campaign.

Bachmann’s presidential campaign, which ended after a lackluster sixth place finish in the Jan. 3, 2012, Iowa caucuses, has already produced a complaint with the Federal Election’s Commission and a lawsuit.

In January, former Bachmann aide Peter Waldron wrote in a letter to the Federal Election Commission that Bachmann’s campaign made improper payments to an Iowa state senator who served as her state chairman. Bachmann for President paid state Sen. Kent Sorenson $7,500 a month, including money through an associated political action committee, Waldron wrote in a letter to the FEC.

Waldron’s letter also alleged that unpaid staffers and contractors were required to sign a non-disclosure agreement prohibiting interviews with attorneys or law enforcement before checking with the campaign.

Bachmann’s attorney, McGinley, has previously denied Waldron’s allegations. Sorenson has also said he violated no state or federal campaign laws while serving as Bachmann’s chairman. Waldron was Bachmann’s national field coordinator from July 2011 to January 2012.

Dan Kotman, Bachmann campaign spokesman, told the St. Cloud Times: “the disclosure of the existence of this review is a predictable and politically motivated attack by Congresswoman Bachmann’s political adversaries in an attempt to disparage her reputation as a top-target of the DCCC (Democratic Congressional Campaign Committee) and Democratic Super PACs. They are willing to do or say anything in an attempt to defeat her in 2014.”

In July 2012, another former Bachmann campaign staffer, Barb Heki, sued Bachmann and her campaign, alleging that Sorenson stole a private email list and used it without permission.

Bachmann announced her presidential bid in June 2011, portraying herself as the race’s true conservative candidate. She won the Ames, Iowa straw poll in August 2011, but dropped out the day after the Iowa caucuses.

Bachmann then announced she would run for re-election to her U.S. House seat and won a surprisingly close contest by just over 4,000 votes.