Legal costs associated with a Minnesota Senate scandal involving a former Republican leader and her senior aide have nearly doubled, a new invoice made public Tuesday showed.

The Associated Press obtained the invoice -- prepared by the Senate's private attorney -- that contains $90,000 in new expenses. It brings the overall cost to just under $200,000.

Former senior staffer Michael Brodkorb sued in the summer over his firing, which came in December 2011 after his affair with then-Senate Majority Leader Amy Koch became public. He argued that female employees in similar relationships didn't lose their jobs. Some of Brodkorb's legal claims have been dismissed.

The case was a headache for state Republicans throughout the fall campaign, with DFLers highlighting aspects of it as a sign of the party's management problems. The scandal showed up in literature used against some Republican senators seeking re-election; Koch did not run again and spent the past year away from the limelight after relinquishing her leadership role.

Top senators are scheduled to meet Thursday to review the invoice and sign off on its payment. It's the last such hearing before Republicans hand over power to a new DFL majority in January.

DFL Sen. Tom Bakk, the incoming majority leader, said his party has been kept mostly in the dark about the status of the case. He said he needs more information before determining whether it makes more financial sense to settle the case or let it drag on in the courts.

"Are we any closer to a settlement? Are we any closer to a resolution?" Bakk asked rhetorically. "I need to talk to our attorney about where we're at."

A call to Brodkorb's attorney was not immediately returned Tuesday.

The new invoice covers costs from August through the end of October. During that period, there were attempts to reach an out-of-court settlement that ended up collapsing.

Most of the billing by the firm Larkin Hoffman Daly and Lindgren covers legal research, preparation of briefs and conferences involving key players. There also are charges for reviewing footage of interviews Brodkorb granted to media outlets in mid-October.