Hillary Clinton has blamed FBI director James Comey for her stunning defeat in the US presidential election in a conference call with her top campaign funders, according to two participants on the call.
Ms Clinton was projected by nearly every national public opinion poll as the heavy favourite going into Tuesday's race.
Instead, Republican Donald Trump won the election, shocking many throughout the nation and prompting widespread protests.
Ms Clinton has kept a low profile since her defeat after delivering her concession speech on Wednesday morning.
On the phone call with supporters on Saturday, Ms Clinton said her campaign and the national party had raised US$900 million from more than 3 million individual donors, according to the two participants who spoke to Reuters.
Ms Clinton said Mr Comey was at fault for her loss after he decided to send a letter to Congress only days before the election announcing that he was reinstating an investigation into whether she mishandled classified information when she used a private email server while secretary of state from 2009 to 2012.
Mr Comey announced a week later that he had reviewed emails and continued to believe she should not be prosecuted, but the political damage was already done.
Ms Clinton told donors that Mr Trump was able to seize on both of Mr Comey's announcements and use them to attack her, according to two participants on the call.
While the second letter cleared her of wrongdoing, Ms Clinton said that reinforced to Mr Trump's supporters that the system was rigged in her favour and motivated them to mobilise on Election Day.