WASHINGTON (NewsNation) — Republicans have dialed up the pressure even more with the investigation into President Joe Biden and his family business dealings. 

House Speaker Kevin McCarthy, R- Calif., said the findings of the probes are rising to the level of an impeachment inquiry, and now, House Oversight Committee chairman Rep. James Comer, R- Ky., said he will call for closed-door testimony from one of Hunter Biden‘s former business partners.

The investigation, led by Comer, revolves around allegations that then-Vice President Joe Biden took part in a bribery scheme connected to his son’s business relationship with Ukrainian energy company Burisma. 

Sen. Chuck Grassley, R- Iowa, recently released an FBI document to the public that detailed unverified reports of conversations between a confidential informant and the CEO of Burisma, who thought putting Hunter Biden on the company’s board could help protect the company from an investigation in Ukraine.

In a tweet on Monday, the House Oversight Committee GOP wrote that in at least a dozen instances, Hunter put his father — then vice president — on speakerphone with his overseas business partners.

“In one instance with Biden associate Devon Archer, two Burisma executives explicitly asked Hunter, ‘Can you ring your dad?’ We look forward to speaking with Devon Archer about this developing story,” the tweet continued.

On Monday, the White House press secretary denied the allegations. 

“The answer is not going to change. The answer remains the same. The president was never in business with his son. I just don’t have anything else to add,” White House press secretary Karine Jean-Pierre said.

Hunter will be in Delaware on Wednesday to plead guilty to charges of failing to pay his taxes. He signed off on a pre-trial diversion program where he avoids jail time for lying on a gun permit about prior drug use.

Some Republicans called this a sweetheart deal while zeroing in on recent testimony from two IRS whistleblowers who alleged that Hunter received preferential treatment from the Department of Justice during the investigation.

However, the lead U.S. attorney in the case also came out saying he had full control over the investigation. 

Overnight, the DOJ wrote that the lead U.S. attorney will be available starting in late September to testify in front of Congress, with the department concerned about the misrepresentation of the Hunter Biden probe. 

Aside from that court hearing with Hunter, the testimony from his former business partner could also take place as soon as later this week on Capitol Hill. 

Democrats continue to say that Republicans still have not shown any true evidence of wrongdoing.