Donald Trump's personal lawyer has filed a defamation lawsuit against BuzzFeed for publishing an unverified dossier of allegations about the president's White House campaign and Russia.
The lawyer Michael Cohen, filed the lawsuit in New York state on Tuesday, nearly a year after BuzzFeed published the dossier commissioned by political opposition research firm Fusion GPS.
Mr Cohen, who is named in the dossier, says BuzzFeed and several of its staffers defamed him by publishing the 35-page document.
He wrote in the lawsuit that BuzzFeed published the unverified allegations "without attempting to determine the veracity of these reports with plaintiff himself".
BuzzFeed spokesman Matt Mittenthal defended the publication of the dossier and added: "We look forward to defending our First Amendment rights in court."
BuzzFeed's top editor has said he is "proud" that the organisation published the dossier.
Ben Smith wrote in an opinion column in The New York Times that it is clear "the dossier is unquestionably real news".
He argued the investigation into Russian interference in the 2016 US election has become the "central challenge to Mr Trump's presidency" and that publishing the dossier last year was in the "public interest".
Democratic Senator Dianne Feinstein of California has released a transcript from the Senate Judiciary Committee's August interview with a co-founder of Fusion GPS.
Donald Trump took to Twitter this afternoon to address the issue:
The fact that Sneaky Dianne Feinstein, who has on numerous occasions stated that collusion between Trump/Russia has not been found, would release testimony in such an underhanded and possibly illegal way, totally without authorization, is a disgrace. Must have tough Primary!— Donald J. Trump (@realDonaldTrump) January 10, 2018
The single greatest Witch Hunt in American history continues. There was no collusion, everybody including the Dems knows there was no collusion, & yet on and on it goes. Russia & the world is laughing at the stupidity they are witnessing. Republicans should finally take control!— Donald J. Trump (@realDonaldTrump) January 10, 2018