A federal investigation is looking into claims that Mollohan gave earmarks to friends and business partners as rewards for campaign donations or lucrative real-estate deals. The allegations were first made by the National Legal and Policy Center, a conservative group based in Virginia.

On Tuesday, Mollohan released a chronology of the real-estate transactions that he and his wife, Barbara, made from 1999 to 2005 to explain how his assets grew from no more than $565,000 in 2000 to more than $6 million in 2004. The review was conducted by the congressman's accounting firm, Braund Eiler & Vasko. The documents also contain a letter to the House clerk to amend some errors in a previous financial disclosure form.

"The documents prove that the National Legal and Policy Center has wildly exaggerated the inadvertent errors on my past financial disclosure statements," Mollohan said in a statement. "They also show that NLPC is dead wrong in implying that I have improperly benefited from my office." Mollohan said that the group ignored that he received a sizable inheritance and that he and his wife did well in a rising real-estate market. "It is those factors that are responsible for the increase of our assets."

Chris Wakim, Mollohan's Republican challenger, who repeatedly calls attention to the controversy, used the opportunity to denounce his opponent. He dismissed the congressman's explanations without detailing anything specifically wrong with them. "West Virginians were forced to accept excuses from their leaders for far too long," he says in a statement released to the media shortly after Mollohan released the documents. "It's time for new leaders."