The shock move comes days after Comey testified on Capitol Hill about the FBI's investigation into Russia's election meddling and a possible collusion between the country and Trump's campaign.
The White House has said there is no evidence of a Trump-Russia collusion, hours after the Federal Bureau of Investigation confirmed that it was probing Russia's meddling in last year's presidential polls, including possible links between the Trump campaign and Moscow.
Clinton and her campaign pressed America's top cop, FBI Director James Comey, to put out the "full and complete facts" about a renewed probe into a cache of recently discovered emails, as the development emboldened Republican rival Donald Trump to seize on to the reignited controversy.
"I was on the way to winning until the combination of Jim Comey's (sic) letter on October 28th and Russian WikiLeaks raised doubts in the minds of people," she said.
The White House previously said Trump only decided to oust Comey after meeting with Attorney General Jeff Sessions on Monday and Deputy Attorney General Rod Rosenstein, who discussed reasons for removing the director.
Investigators have also been looking for any evidence of possible financial crimes by Trump associates.
The President has maintained that he has nothing to do with Russia.
Clinton has blamed her presidential election loss on the "unprecedented" events of Russian cyber hacking and the Federal Bureau of Investigation's probe into her use of her personal e-mail server.
The announcement by Attorney General Jeff Sessions comes within days of President Donald Trump firing his Secretary of State Rex Tillerson.
The agency's director told lawmakers that it hasn't changed its opinion that Hillary Clinton should not face criminal charges after a review of new e-mails.
"I just fired the head of the FBI. He was crazy, a real nut job," Trump told Lavrov, according to a media report.
The news report was immediately refuted by both the Secretary of State Rex Tillerson and the National Security Advisor, who said that there was no discussion of specific threats with the Russians.
'Huma Abedin must follow through in the footsteps of her illustrious mentor Hillary Clinton to carry the movement forward to empower American women,' says Kaleem Kawaja.