(CNN) - The Defense Department’s inspector general will review the academic investigation of plagiarism allegations against Sen. John Walsh.
The Montana Democrat is accused of not properly attributing certain material in a paper to complete his master's degree at the Army War College.
Carol Kerr, the school’s spokeswoman, said it would launch an Academic Review Board to look into the matter.
The results and any recommendations will be forwarded to the Defense Department IG for its “consideration.”
The New York Times first reported last week that a review of a 2007 final paper suggests the decorated Iraq war veteran “appropriated at least a quarter of his thesis on American Middle East policy from other authors’ works, with no attribution.”
Material from a Carnegie Endowment for International Peace report and a 1998 essay by a Harvard scholar were included in the paper without proper sourcing, the Times reported.
Walsh's reelection campaign acknowledged "the citations were not all done correctly," but insisted it was an "unintentional mistake."
Walsh later told the Associated Press he was suffering from post-traumatic stress after his Iraq deployment.
Kerr said it is "standard policy" for the Pentagon IG to review its work, although this will be the first time the war college's Academic Review Board has convened for a member of Congress.
The board plans to meet no sooner than August 15, after which it will recommend whether punitive action should be taken.
The head of the college will ultimately decide what action is taken in the case.
Walsh also is the former head of Montana’s National Guard and was already facing a tough reelection challenge in the conservative state against GOP candidate Rep. Steve Daines.
The latest controversy further jeopardizes Democratic chances of maintaining control of the Senate, as Republicans must win six seats to overtake them.
Walsh stepped down as Montana's lieutenant governor after he was appointed to the Senate in February to replace Max Baucus, who is now ambassador to China.
CNN's Dana Davidsen, Barbara Starr, Jamie Crawford, Leigh Ann Caldwell and Paul Steinhauser contributed to this report.