House Oversight Committee Chairman James Comer (R-Ky.) said last week that Republican investigators conducting an impeachment inquiry into President Joe Biden will begin honing in on his use of pseudonyms during his time as a U.S. senator and vice president under Barack Obama.

In an interview with Fox News, Comer suggested Biden’s past uses of pseudonyms in email communications was done most likely to hide his true identity. Congressional investigators have found at least three aliases – Robert Peters, Robin Ware, and JRB Ware — they believe were used by Biden when he was serving as vice president, Newsmax reported.

“Right now, I think one of the most important amount of documentation that we need are those pseudonym emails,” Comer told Fox.

“What we did not know until recently was that he was, in fact, using those pseudonym emails to communicate with not just his son, Hunter Biden, but also with his shady business associates,” Comer noted further.

Comer made a request in August to the National Archives for the pseudonym emails and other documentation and asked that the information be provided to Congress in unredacted form. In November, he accused the White House of “withholding” some 82,000 pages of those emails.

Comer told Fox News the 14 pages of emails the White House did allow to be turned over to Congress “didn’t even amount to half of 1 percent” of what he is seeking but added that he wants to give the Biden administration some room to argue that they are not incriminating, Newsmax reported.

In addition, the House impeachment inquiry is examining whether the president engaged in “a conspiracy to obstruct” Congress by allegedly coordinating with his son, Hunter Biden, to blow off a congressional subpoena for closed-door testimony.

“In light of an official statement from the White House that President Biden was aware in advance that his son, Hunter Biden, would knowingly defy two congressional subpoenas, we are compelled to examine as part of our impeachment inquiry whether the President engaged in a conspiracy to obstruct a proceeding of Congress,” a letter to White House Counsel Edward Siskel read.

Hunter Biden defied a lawful deposition issued by the Republican-controlled Congress to appear at a closed-door deposition last month, setting up a potential legal showdown as his father campaigns for a second term.

Fox News reported that Hunter refused to comply with the subpoena issued by the House Oversight Committee and instead held a press conference where he offered again to testify publicly, which is not standard congressional procedure.

He also blasted Republicans while claiming that his father was not “financially involved” with his foreign business dealings. He ripped “MAGA” Republicans who have “invaded” his privacy, “attacked” his family, and “ridiculed my struggle with addiction.”

“They belittled my recovery, and they have tried to dehumanize me, all to embarrass my father, who has devoted his entire life to public service,” the president’s son said. “For six years, I have been a target of the unrelenting Trump attack team. ‘Where’s Hunter?’ Well, here’s my answer. I am here.”

He added that “my father was not financially involved in my business,” noting that Joe was not involved in his dealings with Ukrainian natural gas firm Burisma Holdings or his Chinese investments as well as others throughout the world and the U.S.

“No evidence to support that my father was financially involved in my business because it did not happen,” Hunter Biden said.