US President Donald Trump used Twitter on 26 December to attack his perceived "tainted" opponents in the FBI and the "crooked Hillary" campaign funded by the Democratic National Committee, over the unproven allegations contained in so-called 'dirty dossier'.

The scathing tweet was apparently triggered by Trump having watched a segment on Fox & Friends, one of the president's favourite news talk shows, and one known for its friendly slant on all things Trump.

The president tweeted: "WOW, @foxandfrlends "Dossier is bogus. Clinton Campaign, DNC funded Dossier. FBI CANNOT (after all of this time) VERIFY CLAIMS IN DOSSIER OF RUSSIA/TRUMP COLLUSION. FBI TAINTED." And they used this Crooked Hillary pile of garbage as the basis for going after the Trump Campaign!"

As Newsweek pointed out, the president also addressed his tweet to a bogus Fox & Friends Twitter account.

Trump was referencing the unverified allegations that he had colluded with Russian intelligence before the US election to sabotage Hillary Clinton's presidential campaign.

Compiled for his Republican and Democrat opponents, the dossier also claimed Trump had been compromised by Russia's FSB spy agency when he was secretly filmed with prostitutes at a hotel in Moscow.

The 35-page document was reportedly circulating in Washington for months before BuzzFeed took the controversial decision in January 2017 to publish its entirety. Former MI6 agent, Christopher Steele, who worked as a spy in Moscow for 20 years, was unmasked as its author.

Trump branded the dossier "fake news" and claimed it was a "political witch hunt". He said Steele was a "failed spy". Russian President Vladimir Putin also rejected the dossier's claims.

Trump has renewed his criticism of the FBI as pressure mounts over the Russia investigation and people with links to the Trump campaign are being charged with crimes.

The president was handed fresh material for his acerbic tweets when it was recently revealed that a veteran FBI counterintelligence agent was removed from special counsel Robert Mueller's investigating team because of anti-Trump text messages.

Donald Trump Fists
US President Donald Trump gestures after taking the oath of office during his inauguration at the U.S. Capitol in Washington, U.S., January 20, 2017. REUTERS/Kevin Lamarque