FBI Director James Comey told Congress on Sunday that a review of newly discovered Hillary Clinton's emails has "not changed our conclusions" from earlier this year that she should not face charges.
Comey received heavy criticism for his decision to notify Congress so close to the election that his agency was reviewing the emails after previously telling lawmakers the investigation into Clinton's server had been completed.
Mr Comey's announcement on the newly-discovered tranche of emails caused relief to spread through the Clinton campaign after the investigation threatened to derail her lead over Republican rival Donald Trump.
Seeking to become the first female president, Clinton will end her campaign with a rally in the battleground state of North Carolina at midnight on Monday.
In his Sunday note to Congress, he said the FBI investigative team worked "around the clock" to review of the "large volume of emails - a chore Comey should have done before going to Congress".
A senior law enforcement official, who spoke on condition of anonymity to discuss internal decision-making, said the letter was meant to reflect a conclusion to the email review and not merely a status update. Comey has said the investigation was done without regard to politics, but he also never lost sight of political sensitivities, receiving regular briefings but refusing to comment in public. He made no direct mention of the FBI decision and continued to insist -without evidence - that Clinton would be under investigation during her potential presidency.
But Mr Trump said: "Hillary Clinton is guilty. But so far it is not active buying, as Clinton is likely to maintain a policy that prevents a strong dollar if she is elected, and as economic prospects remain unclear", said Masafumi Yamamoto, chief forex strategist at Mizuho Securities in Tokyo. That fueled the perception that at least some in the bureau, a organization of predominantly white men, might have partisan motivations, and Democrats called for the Justice Department inspector general to look into the matter.
She was careful to avoid giving any indication of her preferred victor in the Trump-Clinton showdown.
Trump has been slamming Clinton for all the celebs who have been appearing with her. "She shouldn't even be allowed to run for president".
"This election will decide the future of life, liberty and faith in America", Trump says in the message.
"He has created a situation where Republicans can hurl innuendo with no basis in fact and there's no way for Hillary Clinton to defend herself".