FBI director challenges Trump’s accusation of Obama wiretap

FBI Director James Comey has asked the justice department to publicly refute US President Donald Trump's accusation that Barack Obama tapped his phone during last year's election campaign, US media reported on Sunday.

The New York Times reported Comey made the request on Saturday because of his concern that the allegation was false and suggested the FBI had broken the law. The report cited senior US officials.

The White House asked Congress, controlled by Trump's fellow Republicans, to examine whether the Obama administration abused its investigative authority during the 2016 US presidential campaign, as part of an ongoing congressional probe into Russia's influence on the election.

Trump on Saturday alleged, without offering supporting evidence, that Obama ordered a wiretap of the phones at Trump's campaign headquarters in Trump Tower in New York.

"There was no such wiretap activity mounted against the president-elect at the time, or as a candidate or against his campaign," former Director of National Intelligence James Clapper, who left his post at the end of Obama's term in office in January, said on NBC's "Meet the Press."

Regardless, White House press secretary Sean Spicer said Trump’s instruction to Congress was based on “very troubling” reports “concerning potentially politically motivated investigations immediately ahead of the 2016 election”.

Spicer did not respond to inquiries about the reports he cited. However, late last week right-wing radio and news sites, including the website recently run by the president’s chief strategist, circulated the idea that Obama had tried to undermine the Trump campaign.

Under US law, a federal court would have to have found probable cause that the target of the surveillance is an "agent of a foreign power" in order to approve a warrant authorising electronic surveillance of Trump Tower.

Democrats accused Trump of trying to distract from the rising controversy about possible ties to Russia. His administration has come under pressure from FBI and congressional investigations into contacts between members of his campaign team and Russian officials.

Attorney General Jeff Sessions bowed out last week of any probe into alleged Russian meddling in the 2016 election after it emerged he met last year with Russia's ambassador while serving as a Trump campaign advisor. Sessions maintained he did nothing wrong by failing to disclose the meetings.