WASHINGTON ― The head of a Democratic lobby shop that represented a Ukrainian energy firm told lawmakers on Monday she was unaware of any involvement by President Joe Biden in his son Hunter’s business deals.

Republicans sought a transcribed interview with Karen Tramontano, CEO of Blue Star Strategies, as part of their impeachment inquiry against Biden. Their chief accusation is that the Ukrainian gas company Burisma bribed Biden for a favor back when he was vice president during the Obama administration.

“Neither Hunter Biden nor then Vice President Joe Biden had any financial or other involvement in my firm’s work with Burisma,” Tramontano told lawmakers, according to an opening statement obtained by HuffPost.

“I am also not aware of any financial arrangements or compensation to then Vice President Biden related to his son’s business dealings with Burisma or otherwise,” Tramontano said.

Tramontano is the latest in a series of witnesses to tell lawmakers they knew of no corruption by the Bidens and hadn’t seen the president get involved in his son’s work. Republicans have struggled to substantiate their bribery allegations, and it’s unclear if they will ever muster enough support for an actual impeachment vote.

Monday’s deposition was actually Tramontano’s second time testifying about Burisma on Capitol Hill. Senate Republicans first talked to her in 2020 as part of their investigation into the very same corruption allegation against Biden. Republican senators that year sought to find out if Biden had pushed for the ouster of a Ukrainian prosecutor in order to protect Burisma because his son served on the company’s board.

State Department officials said ousting the prosecutor was their policy, not Joe Biden’s, and that the prosecutor had wasted U.S. taxpayer dollars by stifling an anti-corruption initiative the U.S. had sponsored. As HuffPost has reported, Tramontano and another Blue Star executive, Sally Painter, testified in that probe that the State Department had a “negative” view of Burisma that they were unable to change. State Department officials said they considered Burisma’s founder corrupt and wanted him prosecuted.

The Senate GOP investigators concluded it was unclear whether Hunter Biden’s work had any effect on U.S. policy.

“To the best of my knowledge, nothing has changed since I provided testimony to the Senate and to the DOJ regarding my firm’s work for Burisma,” Tramontano said Monday. (Separately, the Department of Justice previously investigated Blue Star for failing to register as a foreign agent for its Burisma work.)

Even though Republicans are relitigating Burisma allegations that were debunked both in 2020 and in 2019, when Donald Trump first made them, they have uncovered new material. The lawmakers unearthed an FBI tip sheet in which a confidential source reported that Burisma’s founder claimed to have paid Joe and Hunter Biden $5 million each. The informant said he couldn’t vouch for the claim.

House Republicans last year sifted through thousands of pages of Hunter Biden’s bank records ― as well as thousands of his emails, texts and other material taken from his laptop and phone ― and have not yet produced any evidence of the supposed bribes. (They did find some truck payments.)

Republicans have not indicated they will ask for testimony from State Department officials who previously testified against the Biden corruption allegations.

“We’re looking at statements that Tramontano and Painter made,” House judiciary committee Chair Jim Jordan (R-Ohio) told HuffPost earlier this month. “We’re looking at all that old stuff.”