Federal counterintelligence agents began an investigation of Donald Trump last year that aimed to find out whether the president had a clandestine agenda to help Russia, the New York Times and CNN reported Friday.

The revelation, which the White House called "absurd" in a late-evening statement, suggests that the FBI felt Trump's firing of director James B. Comey in May 2017 was motivated by Russian interests and might constitute a threat to U.S. national security, the Times reported.

While the allegation of Trump's possible collusion with the Russian government has been raised before, to date there has been no evidence.

Rudolph W. Giuliani, a lawyer for the president, was quoted by the Times as saying that the investigation seems to have gone nowhere. “The fact that it goes back a year and a half and nothing came of it that showed a breach of national security means they found nothing,” Giuliani said on Friday.

White House Press Secretary Sarah Sanders said in a statement that Comey was fired for just cause and that Trump has never favored Russia.

“This is absurd. James Comey was fired because he’s a disgraced partisan hack, and his Deputy Andrew McCabe, who was in charge at the time, is a known liar fired by the FBI. Unlike President Obama, who let Russia and other foreign adversaries push America around, President Trump has actually been tough on Russia.”

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The Times and CNN reports both cite unnamed sources.

The decision to investigate Trump himself was an aggressive move by FBI officials who were confronting the chaotic aftermath of the firing of Mr. Comey and enduring the president’s verbal assaults on the Russia investigation as a “witch hunt,” the Times reported.

CNN reported that counterintelligence agents were investigating why Trump was acting in ways that seemed to benefit Russia.

The obstruction probe was an idea the FBI had previously considered, but it didn't start until Comey was fired, CNN reported. The justification went beyond Trump's firing of Comey, CNN said, according to its sources, and included the President's conversation with Comey in the Oval Office asking him to drop the investigation into his former national security adviser Michael Flynn.

Trump insisted last year that he didn't fire FBI Director James Comey because of the Russia investigation, despite video and documentary evidence to the contrary, according to several USA TODAY stories at the time.

"Not that it matters but I never fired James Comey because of Russia!" Trump tweeted shortly after the firing. "The Corrupt Mainstream Media loves to keep pushing that narrative, but they know it is not true!"

The FBI director's firing is central to an obstruction of justice investigation being conducted by special counsel Robert Mueller, who is also looking into Russian attempts to influence the 2016 election in order to help Trump.