Former Vice President Joe Biden should be investigated by the Justice Department for violating federal laws in using his office in 2015 to “coerce” Ukraine to fire its top prosecutor, Rep. Paul Gosar, R-Ariz., said Wednesday.

Gosar, in his fifth term, referenced Biden’s comments in a video last year at the Council of Foreign Relations in arguing that the former vice president might have violated the Foreign Corrupt Practices Act.

“It appears, based on former Vice President Biden’s admission captured on video, that he used his official office to coerce a foreign nation to take action that would personally financially benefit his son,” Gosar said via Twitter. “This is the definition of a corrupt practice.”

In the video, Biden admitted to withholding $1 billion in military aid to Ukraine to force the firing of prosecutor Viktor Shokin.

Shokin, who was later dismissed, had recently completed a probe into the country’s gas producer Burisma Holdings, whose board included Biden’s son Hunter.

Gosar, 60, sits on the House Oversight Committee, one of the six panels House Speaker Nancy Pelosi said Tuesday would be investigating President Donald Trump for impeachment.

The congressman said that Biden’s video remarks represented “a prima facie case” and that “the evidence of then-Vice President Biden’s potential corruption warrants a full investigation by Congress and the Department of Justice.”

In addition, Sen. Rand Paul, R-Ky., appeared to lend credence to Gosar’s position in his own tweet: “Did Biden threaten US aid to Ukraine to enrich his son? Shouldn’t Congress investigate?”