White House Press Secretary Karoline Leavitt accused former first lady Jill Biden of participating in a 'cover up' about her husband's health and said she should speak with House Republican investigators who are ramping up a probe.

'Jill Biden was certainly complicit in that cover up,' Leavitt told reporters at the White House when asked about a House Republican request to a handful of top former Biden administration officials.

'Frankly, the former first lady should certainly speak up about what she saw in regards to her husband and when she saw and what she knew,' Leavitt said.

She teed off on the former first lady when asked about House Oversight Chairman Rep. James Comer's request for four aides and former White House physician Dr. Kevin O'Connor to come in for interviews.

The Trump loyalist and Kentucky Republican is probing allegations launched by Trump and some of his allies that aides were in control of Biden's 'autopen' and shielded the nation from information about his fitness.