Donald Trump’s Justice Department is examining pardons that Joe Biden issued to family members and death row inmates in the final hours of his presidency.
An investigation by the House oversight committee is looking into Mr Biden’s cognitive health and the use of “autopen”.
Former Alabama Attorney Jay Town claims this could be the “worst scandal in the White House in American presidency history”.
“I think the case will actually start to get very solid as we start to engage in what we call discovery, which is where we’re getting evidence through a grand jury or subpoenas,” he told Sky News Australia.
“But I think that once one domino falls, you’re going to see 20 of them fall.”