Two senior U.S. senators have sent a letter to the FBI and Justice Department asking for any information they have on President Donald Trump's claim that his predecessor Barack Obama wiretapped him during the 2016 presidential campaign.
Republican Lindsey Graham and Democrat Sheldon Whitehouse wrote the letter to James Comey, director of the Federal Bureau of Investigation, and Acting Deputy Attorney General Dana Boente.
"We request that the Department of Justice provide us copies of any warrant applications and court orders...related to wiretaps of President Trump, the Trump campaign, or Trump Tower," they said in the letter.
Under U.S. law, presidents cannot direct wiretapping. The federal government can ask a court to authorize wiretapping, but it must provide justification.
Asked at a news briefing on March 8 if Trump was the subject of a probe, White House spokesman Sean Spicer replied: "There is no reason that we have to think that the president is the target of any investigation whatsoever."
Critics of Trump have accused him of launching the wiretap allegation in order to deflect attention from investigations into his administration's possible ties to Russia.
Some voices in the Congress have likened it to Trump's long-held contention that Obama was not born in the United States and thus did not legitimately hold the office of president -- an accusation he did not withdraw until 2016.