Rep. Jesse Jackson Jr. (D-Ill.) has spent an additional $15,000 to cover his legal expenses, according to first-quarter 2009 campaign finance reports released Monday.

The January payment is the second made to Chicago-based attorney James Montgomery since mid-December, when Jackson was first identified as “Senate Candidate Number Five— in the Justice Department’s investigation of a pay-to-play scheme by then-Gov. Rod Blagojevich (D). Blagojevich has since been impeached from office over the scandal, which involved his trying to sell President Barack Obama’s then-vacant Senate seat to the highest bidder.

Jackson’s campaign paid $100,000 to Montgomery on Dec. 18, according to Federal Election Commission records.

Jackson was one of several Democrats interested in the Senate appointment, and he had met Blagojevich before federal officials arrested the former governor late last year.

Jackson, who has denied any wrongdoing, acknowledged in December that he had been contacted by the U.S. Attorney’s Office, and he confirmed last week that the Office of Congressional Ethics has also opened a probe into the matter.

The OCE, established by House lawmakers in early 2008, is tasked with reviewing and recommending potential ethics violations to the House Committee on Standards of Official Conduct.

Blagojevich appeared at his arraignment Tuesday and pleaded not guilty in an Illinois federal courtroom.