Hillary Clinton boosted as election hits final day after FBI said they found no incriminating evidence among new emails

US Democratic presidential candidate Hillary Clinton has been given a breath of fresh air as she heads into the final day for the White House race against Republican candidate Donald Trump with new momentum after the FBI said they found no incriminating evidence in the probe of her new email scandal.

FBI Director James Comey on Sunday told Congress that investigators had worked "around the clock" to complete a review of the recently discovered emails by Hillary Clinton and thus found no reason to change their July finding that Clinton was not guilty of criminal wrongdoing in her use of a private email server while she was secretary of states, an outcome that sent shockwaves through the race as both candidates try to closeup on a handful of key battleground states that could swing the election in their favour.

Clinton's Democratic allies now hope that the FBI finding would swing voters in her favour and enough to push her to the finish line.

"The FBI's swift and thorough review should finally close the door on this Republican sideshow,"said House Democratic leader Nancy Pelosi, before adding that the election would now be decided "on the merits of the candidates" rather than innuendo.

The FBI findings did not go down well with Trump who insisted at a rally in Detroit on Sunday that it would have been impossible for the FBI to review a reported 650,000 emails in so short a time, claiming she's being protected by "a rigged system."

"Hillary Clinton is guilty. She knows it, The FBI knows it. The people know it" Trump said.

The people know it,” it’s now up to “the American people to deliver justice at the ballot box on November 8” he added.