He also claimed notes reportedly kept by former FBI leaders about their interactions with him are 'fake memos'
Donald Trump has hit out at the US special counsel investigation into alleged Russian interference in the 2016 presidential election.
The special counsel investigation is being led by Robert S Mueller III, a former director of the FBI.
While set up to investigate alleged Russian interference and any links between the Russian government and members of the Trump campaign, it has expanded beyond its original remit to also look into issues such as alleged money laundering.
The wide-ranging probe has already seen a number of charges and indictments - including against former Trump campaign manager Paul Manafort and former White House national security adviser Michael Flynn.
Mr Manafort has pleaded not guilty to charges including conspiring to launder money, while Mr Flynn has pleaded guilty to lying to the FBI about conversiations with a Russian ambassador in 2016.
The US President this weekend claimed the probe 'should never have been started'.
In a tweet, he claimed: "The Mueller probe should never have been started in that there was no collusion and there was no crime.
"It was based on fraudulent activities and a Fake Dossier paid for by Crooked Hillary and the DNC, and improperly used in FISA COURT for surveillance of my campaign. WITCH HUNT!"
Washington Post fact-checker Glenn Kessler described the tweet as 'inaccurate on many levels':
6. Many people who worked for Trump in the campaign now face criminal liability or have pleaded guilty. So Mueller is uncovering malfeasance. A real witch hunt would have nothing to show for itself.— Glenn Kessler (@GlennKesslerWP) March 18, 2018
In a subsequent tweet early Sunday morning, President Trump claimed:
Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and Zero Republicans? Another Dem recently added...does anyone think this is fair? And yet, there is NO COLLUSION!— Donald J. Trump (@realDonaldTrump) March 18, 2018
Mr Mueller himself is a Republican, who was initially appointed to lead the FBI by George W Bush.
President Trump also continued his social media commentary about the former FBI deputy director Andrew McCabe, who was fired on Friday less than two days before he could retire from the bureau.
US media reported this weekend that Mr McCabe - who was fired by Attorney General Jeff Sessions on the back of a recommendation from an internal FBI review - had kept notes of his interactions with President Trump, similar to those apparently kept by former FBI director James Comey before his own firing by the Trump administration.
President Trump responded to the reports on Twitter, saying: "Spent very little time with Andrew McCabe, but he never took notes when he was with me.
"I don’t believe he made memos except to help his own agenda, probably at a later date. Same with lying James Comey. Can we call them Fake Memos?"
Mr Comey, meanwhile, took to Twitter himself on Saturday to address President Trump:
Mr. President, the American people will hear my story very soon. And they can judge for themselves who is honorable and who is not.— James Comey (@Comey) March 17, 2018