President Joe Biden has repeatedly claimed that he had no knowledge of his son Hunter’s business dealings, but House Republicans continue to find evidence to the contrary.

On Thursday, House Oversight Committee Chairman James Comer (R-Ky.) demanded that the National Archives and Records Administration to produce all documents and communications in which then-VP Biden  used pseudonyms such as “Robert Peters,” “Robin Ware,” and “JRB Ware.”

Comer’s letter to NARA covers a timeframe when Biden’s vice presidential duties regarding Ukraine overlapped with his son’s business dealings in that country.

According to Comer, the committee has already reviewed an email containing an attachment showing the vice president’s schedule. This attachment indicates that he had a phone conversation with then-Ukrainian President Petro Poroshenko. The email was addressed to a recipient named “Robert L. Peters” and copied to the vice president’s son, Hunter Biden, Breitbart reported.

The House Oversight Committee contends that in 2015, Joe Biden purportedly issued a threat to withhold U.S. aid to Ukraine unless the Ukrainian president dismissed prosecutor Viktor Shokin, who was overseeing an investigation into the Ukrainian energy company Burisma Holdings.

“Burisma paid Hunter Biden $83,000 a month for a board position to obtain the Biden ‘brand,’ as Biden business associate Devon Archer described the arrangement,” Breitbart added.

About three years later, in 2018, Biden bragged about getting Shokin fired, which he pushed for during an official visit to Ukraine in 2015.

“I said, ‘I’m telling you, you’re not getting the billion dollars.’ I said, ‘you’re not getting the billion. I’m going to be leaving here in, I think it was about six hours,’” Biden told an audience at an event hosted by the Council on Foreign Relations. “I looked at them and said, ‘I’m leaving in six hours. If the prosecutor is not fired, you’re not getting the money.’ Well, son of a bitch. He got fired.”

Breitbart added:

On Tuesday, Comer issued a request to NARA for all unredacted materials in which then-Vice President Joe Biden used a pseudonym related to his relationship with Ukraine. Comer explained he specifically seeks an email titled, “Email Messages To and/or From Vice President Biden and Hunter Biden related to Burisma and Ukraine.” Comer said the email, attached with a document, was sent to “Robert L. Peters”— a pseudonym for Joe Biden.

“Joe Biden has stated there was ‘an absolute wall’ between his family’s foreign business schemes and his duties as Vice President, but evidence reveals that access was wide open for his family’s influence peddling,” Comer noted in a statement. “The National Archives must provide these unredacted records to further our investigation into the Biden family’s corruption.”

“We already have evidence of then-Vice President Biden speaking, dining, and having coffee with his son’s foreign business associates,” he said. “We also know that Hunter Biden and his associates were informed of then-Vice President Biden’s official government duties in countries where they had a financial interest.”