WASHINGTON - A former Republican staffer fired from the House Benghazi committee filed a lawsuit against the panel's GOP chairman Monday in an escalating dispute over the investigation of the 2012 deadly attacks in Benghazi, Libya.

Air Force Reserve Maj. Bradley Podliska said in a complaint filed in federal court that Rep. Trey Gowdy of South Carolina made false statements about him after Podliska announced last month he was suing the committee for wrongful termination.

Podliska made a draft complaint public at the time. But the lawsuit was not formally filed until Monday, said Peter Romer-Friedman, one of Podliska's attorneys.

Gowdy said last month that Podliska was fired for mishandling classified information. Podliska denies that, and his suit claims Gowdy defamed him and harmed his career prospects.

Podliska says Gowdy's committee was engaged in a partisan investigation of the Benghazi attacks, which killed four Americans, including Ambassador Chris Stevens.

Gowdy has disputed that, saying Podliska was overly focused on Democratic presidential candidate Hillary Rodham Clinton. She was secretary of state at the time of the attacks.

Jamal Ware, a spokesman for the Benghazi committee, said the panel disagrees strongly with Podliska's claims, which he called "meritless" and improper.

"The committee did not and does not discriminate or retaliate based on military service, military status or any other unlawful factor," Ware said. "We look forward to responding to the allegations in due course and in the appropriate forum. And we are confident that once all the facts are known we will be fully exonerated."

Podliska's lawsuit says Gowdy knew his statements about Podliska were false or he was "reckless in disregard" to whether the statements were true or false.

Podliska's initial complaint emerged days before Clinton's high-profile testimony to the Benghazi panel on Oct. 22 and amid fierce partisan fighting about the true nature of the GOP-led investigation.

Gowdy and other Republicans say the committee has been and remains focused on those killed in Benghazi and on providing a definitive account of the attacks.