James Comey, the head of the Federal Bureau of Investigation, has told Congress that his agency stands by its July decision not to recommend prosecution of Hillary Clinton over the scandal involving her use of a private email server as secretary of state.

Mr Comey sparked massive controversy two weeks ago when he informed Congress that the FBI was examining new emails related to its prior investigation of Mrs Clinton, amid concerns that the agency was getting involved in the politics of the election.

While the examination of the new emails — which were found on the computer of Anthony Weiner, the estranged husband of top Clinton aide Huma Abedin — was expected to take weeks, Mr Comey on Sunday wrote to Congress to inform them that his agents had completed their investigation.