A report claims that the FBI was so alarmed by the behaviour of US President Donald Trump, they investigated whether he was working on behalf of Russia.
The New York Times says a counter-intelligence investigation was launched after Mr Trump fired FBI director James Comey in 2017.
Investigators were looking into whether the President's actions were a threat to national security, and whether Mr Trump "was knowingly working for Russia or had unwittingly fallen under Moscow's influence".
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Two days after the firing, Mr Trump told NBC News he did it to stop the FBI's investigation into his alleged links with Russia.
"I was going to fire Comey knowing there was no good time to do it," he said. "And in fact, when I decided to just do it, I said to myself - I said, you know, this Russia thing with Trump and Russia is a made-up story. It's an excuse by the Democrats for having lost an election that they should've won."
Soon after, he told Russian officials Mr Comey was "a real nut job" and the "pressure because of Russia" was "taken off".
The case was handed over to special counsel Robert Muller, but it's not clear what happened after that.
Russia has been accused of meddling in the US election through a sophisticated operation of targeted social media advertising and an army of online trolls posing as US citizens, aiming to create dischord.
Mr Trump's lawyer, former New York Mayor Rudy Giuliani, told the Times the FBI "found nothing", but admitted he doesn't know what Mr Meuller's investigation may have found over the past 18 months.
Mr Trump tweeted that the day he fired Mr Comey was "a great day for America", and the FBI has "NO interest in going after the Real Collusion (and much more) by Crooked Hillary Clinton, her Campaign, and the Democratic National Committee".
"As I have often said, getting along with Russia is a good thing, not a bad thing."
None of Mr Trump's allegations about Ms Clinton have been proven true.
Mr Trump has repeatedly denied collusion with Moscow, despite a growing amount of circumstantial evidence. Many of his former aides and advisers have been found to have links to powerful Russian figures.