Donald Trump has again demanded Presidential frontrunner Joe Biden be investigated for unspecified crimes, two weeks out from the election.

Such an investigation would be against Justice Department policy which probibits them from taking actions which could interfere with an election campaign.

The President, who trails by up to ten points in national polls, called on Attorney General Bill Barr to appoint a special prosecutor to investigate the former Vice President.

Citing a heavily disputed New York Post story concerning the business dealings of Biden's son, Hunter, the President has repeatedly branded his opponent a member of an "organised crime family" in recent days.

Biden dismissed the attacks as a "smear campaign."

Yet in a call-in interview with Fox News, Trump said a special prosecutor should be appointed before the 3 November election.

He said: "We've got to get the Attorney General to act. And he's got to act fast. And he's got to appoint somebody."

President Donald Trump returns to the White House on Marine One after multiple campaign stops over the weekend (
Image:
Getty Images)

He added: "This is major corruption and this has to be known about before the election".

Trump and his supporters repeatedly called for Hilary Clinton to be "locked up" ahead of the 2016 election.

Yesterday, the President told a rally in Arizona that Biden was "lucky" he had not already been locked up.

But today during a speech in Arizona, Trump said: "He is lucky that we have in our country, a wonderful human being and the most fair Attorney General of the United States, because I know people who would have had him locked up five weeks ago."

He said Attorney General (AG) Bill Barr was "a very nice man and a very fair man and they have no idea, because somebody would have taken that thing, and all the crap and corruption, he's been a corrupt politician for a long time, this guy."

He provided no evidence for his claim that Biden is "corrupt."