A top US senator has vowed to get to the bottom of allegations that discussions were held in 2017 on removing President Donald Trump from office.
The chairman of the US Senate Judiciary Committee, Lindsey Graham, was reacting to an interview by former acting FBI chief Andrew McCabe.
Mr McCabe told CBS' 60 Minutes that deputy US attorney general Rod Rosenstein discussed the numbers needed to invoke the 25th Amendment.
The New York Times last year reported a similar claim.
The amendment, which has never been used, empowers a majority of cabinet members to remove a president if deemed unfit for office.
It was allegedly brought up by Mr Rosenstein after Donald Trump fired FBI director James Comey.
'Very concerned about the president'
Mr McCabe said: "The discussion of the 25th Amendment was simply... Rod raised the issue and discussed it with me in the context of thinking about how many other cabinet officials might support such an effort.
The deputy attorney general was definitely very concerned about the president, about his capacity and about his intent at that point in time.
He added that the conversation happened at an "unbelievably stressful time", and the idea was simply 'thrown out' during 'frenzied, chaotic' conversations about the next steps.
Responding to the comments, Senator Graham pledged to hold hearings on the issue.
He told CBS' Face The Nation programme: "The deputy attorney general denies it. So I promise your viewers the following, that we will have a hearing about who's telling the truth, what actually happened.
"I'm going to do everything I can to get to the bottom of the Department of Justice FBI behavior toward President Trump and his campaign."