Washington (CNN) Hillary Clinton was unaware of the now-infamous dossier of allegations about Donald Trump and Russia prior to Buzzfeed's publishing of the document earlier this year, a source familiar with the matter has told CNN.

Clinton was disappointed that the research from the document was not made public before she lost the 2016 election, the source said.

The New York Times first reported on Wednesday that Clinton didn't know about the dossier until it was published, citing two associates who discussed the matter with her.

The news comes a day after the law firm representing the Clinton campaign and the Democratic National Committee acknowledged it helped fund opposition research on President Donald Trump that ultimately resulted in the dossier.

CNN reported Tuesday that a source familiar with the matter said the law firm retained the intelligence firm Fusion GPS and entered "into an engagement for research services that began in April 2016 and concluded before the election in early November."

CNN has previously reported that the Fusion efforts researching Trump were first funded by Republican foes of Trump, and Democrats began paying the research firm later on, after Trump became the presumptive nominee. The identity of the Republican client or clients has not yet been publicly revealed.

Clinton is not the only high-profile Democrat to deny knowledge of the document before it was published.

The Clinton campaign's national press secretary, Brian Fallon, tweeted Tuesday about the reported tie between the campaign and the dossier.

"I regret I didn't know about Christopher Steele's hiring pre-election," he tweeted , referring to the former British intelligence agent who authored the dossier. "If I had, I would have volunteered to go to Europe and try to help him."

"If I'd gotten his dossier before Nov 8, I may have tried to convince Mook & Podesta to let me hold a Comey-style press conference to read it," Fallon, who is now a CNN political contributor, tweeted

DNC communications director Xochitl Hinojosa said in a statement Tuesday: "Tom Perez and the new leadership of the DNC were not involved in any decision-making regarding Fusion GPS, nor were they aware that Perkins Coie was working with the organization."

"But let's be clear, there is a serious federal investigation into the Trump campaign's ties to Russia, and the American public deserves to know what happened," the statement read.

Trump also made mention of the dossier this week , calling Clinton's and others' denial of having any knowledge of it a "disgrace."

"Hillary Clinton always denied it. The Democrats always denied it, and now, only because it is going to come out in a court case, they said yes they did it. They admitted it and they are embarrassed by it. I think it is a disgrace," Trump said Wednesday.

CORRECTION: A previous version of this story misspelled Fusion GPS.