DONALD Trump has launched a personal attack on former special counsel Robert Mueller after the former special counsel said investigators could not conclude the president had not committed a crime.

He described the man who led the inquiry into alleged Russian interference in the 2016 US election as "totally conflicted" and that he "wanted to be the FBI director, and I said 'no'".

The president also claimed the two had had a "business dispute".

Mr Mueller denied on Wednesday, that his inquiry had concluded that Trump is innocent, saying: “If we had confidence that the president clearly did not commit a crime, we would have said that.”

His comments - his first public statement on his inquiry - prompted Democratic presidential candidates to call for the Republican president to be impeached.

The Democratic leadership of the House of Representatives is sceptical of such a move.

HeraldScotland:

At the White House on Thursday morning, Mr Trump said impeachment was a "dirty, filthy disgusting word".

He said Mr Mueller was a "true Never Trumper", referring to his Republican critics during the 2016 White House race, and that his investigation was "a giant presidential harassment".

Speaking to reporters Mr Trump said:“I think he is a total conflicted person. Mueller is a true never-Trumper. He’s somebody that dislikes Donald Trump.  He said, essentially,‘you’re innocent.’ There was no crime, there was no charge because he had no information.”

And as he prepared to board a helicopter to Colorado to address military graduates, Mr Trump said: "Robert Mueller should never have been chosen because he wanted the FBI job and he didn't get it and the next day he was picked as special counsel.

"Plus we had a business dispute."

The president also said that he did not believe that Russian interference helped him get elected. “You know who got me elected?  I got me elected,” he said. “Russia didn’t help me at all. Russia, if anything, I think, helped the other side.

HeraldScotland:

"There was no high crime and there was no misdemeanour, so how do you impeach based on that."

Mr Mueller - who was FBI director under President George W Bush - said on Wednesday that charging a sitting president with a crime "is not an option" due to a long-standing US Department of Justice policy.

"If we had had confidence that the president clearly did not commit a crime, we would have said so," Mr Mueller declared, contradicting Mr Trump's claims of exoneration.

The special counsel's 448-page report issued in April did not establish that Mr Trump conspired with Russia to sway the White House election, but listed 10 possible instances of obstruction of justice by the president.