James Comey, the FBI director, said he felt 'nauseous' at the thought that he affected the result of last year's US presidential election by reopening a probe into Hillary Clinton's emails days before the vote.

Eleven days before Donald Trump won the race to the White House, Mr Comey announced the decision to reopen the investigation into Mrs Clinton's use of a private email server, which led to damaging headlines for the Democratic candidate. Mrs Clinton has since blamed the FBI director for costing her the presidency.

But Mr Comey, in the most extensive comments yet defending his actions, said it would have been far worse to conceal his decision. Mr Comey, appearing before the Senate Judiciary Committee, said: "It makes me mildly nauseous to think that we might have had some impact on the election but honestly it wouldn't change the decision.

"I've had a lot of rocks thrown at me but I've done the right thing. I don't have any regrets."