Michael Cohen, Trump's personal attorney, files lawsuits against Fusion GPS, BuzzFeed over infamous 'dossier' BuzzFeed published the 35-page document in its entirety in January 2017.

 -- Michael Cohen, Donald Trump’s personal attorney and close confidant, says he filed a pair of lawsuits on Tuesday, one in federal court against the private investigative firm Fusion GPS and the other in state court against the popular website BuzzFeed.

In both suits, Cohen claims that the infamous dossier of salacious but unconfirmed allegations of collusion between members of the Trump campaign and Russian agents compiled by Fusion GPS and later published by BuzzFeed contained “false and defamatory” allegations that resulted in “harm to his personal and professional reputation, current business interests, and the impairment of business opportunities.”

According to the federal complaint, Fusion GPS, co-founded by former Wall Street Journal reporter Glenn Simpson, “recklessly placed [the dossier] beyond their control and allowed it to fall into the hands of media devoted to breaking news on the hottest subject of the day: the Trump candidacy.”

According to the New York state complaint, which names BuzzFeed’s top editor Ben Smith as well as Ken Bensinger, Miriam Elder and Mark Schoofs, Cohen claims “even though Defendant Buzzfeed expressly acknowledged the unverified (and potentially unverifiable) nature of the Dossier's allegations, Defendant BuzzFeed published the un-redacted Dossier and the Article anyway — without attempting to determine the veracity of these reports with Plaintiff himself.”

When reached for comment, a BuzzFeed News spokesperson defended the news organization’s decision to publish the document.

“The dossier is, and continues to be, the subject of active investigations by Congress and intelligence agencies,” wrote BuzzFeed News spokesperson Matt Mittenthal in an email. “It was presented to two successive presidents, and has been described in detail by news outlets around the world. Its interest to the public is obvious. This is not the first time Trump's personal lawyer has attacked the free press, and we look forward to defending our First Amendment rights in court."

A spokesperson for Fusion GPS did not respond to requests for comment.

Cohen tweeted Tuesday evening: "Enough is enough of the #fake #RussianDossier. Just filed a defamation action against @BuzzFeedNews for publishing the lie filled document on @POTUS @realDonaldTrump and me!"

Fusion GPS was hired — first by Republicans and later by Democrats — to conduct research into then-candidate Trump. The dossier contains unverified information compiled by former British intelligence officer Christopher Steele on behalf of the investigative firm.

BuzzFeed published the 35-page document in its entirety in January 2017, noting that the “allegations are unverified, and the report contains errors,” but “Americans can make up their own minds about allegations about the president-elect that have circulated at the highest levels of the U.S. government.”

The dossier includes allegations Cohen played a key role in the alleged Russian effort to interfere in the 2016 election. Steele recorded claims that Cohen had secret meetings with Kremlin officials in Prague in August 2016, at the height of the campaign, during which he allegedly discussed how to pay Kremlin-associated hackers for their work against the rival Hillary Clinton campaign.

Cohen has forcefully and repeatedly denied any knowledge of any such operation.

“I want to be very clear,” Cohen told ABC News. “I have never been to Prague or the Czech Republic, and I have never engaged with, been paid by, paid for, or communicated with anyone representing the Russian Federation or anyone else to hack anyone or any organization or disseminate false news reports or interfere in any way with this election.”

Cohen has also attracted the interest of congressional investigators probing Russian efforts to interfere in the 2016 election for his role in the negotiations to build a Trump Tower in Moscow in 2015 and 2016. Cohen told ABC News in August that while the Trump Organization seriously considered the proposal, the plan was eventually abandoned.

Cohen appeared behind closed doors before members of the House Intelligence Committee in October. His scheduled appearance before members of the Senate Intelligence Committee in September was postponed, with committee leaders calling for an open session in the “at a date in the near future.”

ABC News’ Matthew Mosk and Alex Hosenball contributed to this report.