WASHINGTON (Reuters) - The U.S. Justice Department said it had no evidence to support the unsubstantiated claim made in March by President Donald Trump that his predecessor, Barack Obama, had ordered a wiretap of Trump Tower during the 2016 presidential campaign.

FILE PHOTO - U.S. President Barack Obama (R) greets President-elect Donald Trump at inauguration ceremonies swearing in Trump as president on the West front of the U.S. Capitol in Washington, U.S., January 20, 2017. REUTERS/Carlos Barria

There has never been any evidence to support Trump’s assertion on Twitter that “Obama had my ‘wires tapped’ in Trump Tower just before the victory,” despite continued insistence from some conservative websites and commentators.

But in a court filing late on Friday, the Justice Department added itself to the list of entities debunking the allegation.

The FBI and the Justice Department’s National Security Division “confirm that they have no records related to wiretaps as described” by tweets from Trump posted on March 4, the department said in a court filing in Washington.

The filing was in response to a Freedom of Information Act lawsuit brought by American Oversight, a government watchdog group.

Trump Tower, a mixed-used New York skyscraper, is home to one of Trump’s private residences and served as his campaign headquarters during the election.

The surveillance claim, which first appeared in conservative media before being picked up by Trump, prompted a rare rebuke by Obama, who responded at the time through a spokesman to denounce the idea that he had ordered surveillance against then-candidate Trump as “simply false.”

In a statement, American Oversight said the Justice Department filing “confirmed in writing that President Trump lied when he tweeted that former President Obama ‘wiretapped’ him at Trump Tower.”

Asked for comment, a White House spokeswoman said on Saturday, “This is not news. We answered this weeks ago.”

Despite the lack of evidence, the White House for several weeks attempted to bolster the baseless claim, and it helped fuel an also unsubstantiated inquiry by Devin Nunes, the Republican chairman of the U.S. House of Representatives intelligence committee, into whether the Obama administration improperly “unmasked” surveillance intercepts of phone conversations Trump associates had with foreigners.