Two key U.S. officials are set to testify publicly about whether there is any truth behind the explosive, but unsubstantiated, claim by U.S. President Donald Trump that former President Barack Obama wiretapped his Trump Tower headquarters in the weeks before last year's presidential election.
Both Federal Bureau of Investigation (FBI) Director James Comey, and National Security Agency chief Admiral Michael Rogers likely would have known about the eavesdropping if it occurred.
They are to appear Monday before the House of Representatives Intelligence Committee as part of a hearing into Russia's efforts to influence last November's presidential election.
For more than two weeks, Trump has refused to back down on his allegation, even as a string of officials, including House Speaker Paul Ryan and the top Republican and Democratic lawmakers on both the Senate and House Intelligence Committees, have said there is no evidence to support Trump's March 4 wiretapping claims he made in a series of Twitter comments.
On Sunday, Republican Congressman Devin Nunes, the chairman of the House panel, told Fox News that new information lawmakers received Friday from the Justice Department about the possibility of a wiretap has not changed his conclusion.
'There never was'
"Was there a physical wiretap of Trump Tower? No, but there never was, and the information we got on Friday continues to lead us in that direction," Nunes said.
Neither Rogers nor Comey has spoken publicly about the president's allegation.
But Comey, as the FBI chief, sought to get the Justice Department, which oversees the FBI, to disavow Trump's claim shortly after the president made it, but the agency has not released any statement.
Attorney General Jeff Sessions, who oversees the Justice Department and was a staunch Trump supporter during the presidential campaign, said last week he never gave the president any reason to believe he was wiretapped in the weeks before the November election.
Trump's White House spokesman, Sean Spicer, last week suggested that the wiretapping was carried out by British agents, citing a statement on Fox News by a legal analyst, Andrew Napolitano.
The British electronic intelligence agency, the GCHQ, said the report was "utterly ridiculous and should be ignored," but when asked about it Friday at a White House news conference, Trump deflected any blame for linking the British to his wiretapping allegation.
"All we did was quote a certain very talented legal mind who was the one responsible for saying that on television,'' Trump said of the claim that Obama had enlisted the British to eavesdrop on him. "You shouldn't be talking to me, you should be talking to Fox."
A short time later, a Fox News anchor said, "Fox News cannot confirm Judge Napolitano's commentary. Fox News knows of no evidence of any kind, that the now president of the United States was surveiled at any time, in any way. Full stop."
Last week, the leaders of of the Senate Intelligence Committee, Republican Richard Burr and Democrat Mark Warner, said in a joint statement, "Based on the information available to us, we see no indications that Trump Tower was the subject of surveillance by any element of the United States government, either before or after Election Day 2016.”
The wiretapping allegation is part of broader investigations by the FBI and lawmakers into the conclusion by the country's intelligence community that Russia meddled in the election in an effort to help Trump defeat his Democratic challenger, former U.S. Secretary of State Hillary Clinton.
U.S. investigators say Russian President Vladimir Putin ordered the hacking into the computers at the Democratic National Committee.
The anti-secrecy group WikiLeaks subsequently released thousands of emails from the files of Clinton campaign chief John Podesta in the month before the election, showing embarrassing, behind-the-scenes efforts of Democratic operatives to help Clinton win the party's presidential nomination.
But the Trump administration has rebuffed any contention that its campaign aides colluded with Russian officials in that cyberattack.