FBI Director James Comey has reportedly rejecting President Donald Trump's accusation that Barack Obama had wiretapped him.
The New York Times reported that Comey asked the Justice Department to publicly reject the claim.
The report cited senior US officials who said Comey made the request because the wiretapping claim was false and must be corrected.
Comey's comments came as the White House asked for a congressional investigation into whether the Obama administration abused its investigative authority during the 2016 campaign amid an ongoing probe into Russia's influence on the election.
Trump on Saturday had accused Obama of tapping Trump Tower phones during the campaign - but cited no evidence.
An Obama spokesman denied the charge.