Wikileaks, the whistle-blowing site founded by Julian Assange, wanted a Republican to become US president, according to a leaked conversation.
Files obtained by The Intercept show the Wikileaks Twitter account revealing its preference to a group of supporters, via private chat.
"We believe it would be much better for GOP [US Republican party] to win," the transcript read.
The account also described Hillary Clinton as a "sadistic sociopath".
It is thought that the Wikileaks Twitter account is controlled by Julian Assange, although it is not clear who wrote the comments in the leaked transcript.
The BBC has contacted the Wikileaks account on Twitter - which has not tweeted since 13 February - but has not yet received a response.
Transcripts from the chat with around ten supporters of Wikileaks also contain disparaging remarks about journalists, including the BBC's Chris Cook, policy editor for Newsnight.
"Please troll this BBC idiot," the Wikileaks account said, before suggesting this might result in Mr Cook tweeting statements that could be used "in legal cases to show that a toxic climate exists [in] the UK".
"This guy clearly has a thin skin and thinks a lot of his clique, which means he can't see how his tweets are dangerous for him," the account added.
Mr Cook said that any trolling that did occur failed to catch his attention.
"I genuinely really didn't notice anything happening against the background noise that BBC reporters get," he told the BBC.
Mr Cook also expressed doubt over the idea that anything he might have tweeted could have been used in a legal case seeking to show, for example, that the UK had mistreated Mr Assange.
According to The Intercept, the transcript of the private group chat on Twitter was leaked by the private group's founder, who uses the pseudonym "Hazelpress".
The news site said it was contacted by Hazelpress after the individual heard that Wikileaks had secretly corresponded with Donald Trump Jr. before the US election in November 2016.
"One of the authors of this article verified the authenticity of the Twitter group messages by logging in using Hazelpress's credentials," The Intercept said.
Julian Assange has been living at the Ecuadorian embassy in London since 2012, where he has avoided an extradition order to Sweden over sexual assault charges in the country.
The charges were dropped in May 2017 but a UK arrest warrant for Mr Assange remains in effect after a Westminster Magistrates' Court judge upheld it on 13 February.