Wikipedia (en)
The Trump–Russia dossier, also known as the Steele dossier, is a private intelligence dossier of 17 memos that were consecutively written from June to December 2016 by Christopher Steele, a former British intelligence (MI6) officer. It contains allegations of misconduct and conspiracy between the Donald Trump campaign and the Russian government before and during the 2016 U.S. presidential election, much of it detailing alleged collusion between the campaign and Russians to interfere in the election to benefit Trump. The contents of the dossier were published in full by BuzzFeed on January 10, 2017. Several mainstream media outlets criticized BuzzFeed's decision to publish the dossier.
The dossier was part of opposition research on Trump during the 2016 U.S. presidential election campaign that was conducted by the American research firm Fusion GPS. This opposition research on Trump was initially funded by a conservative political website, The Washington Free Beacon, before Steele was involved.
After Trump emerged as the probable Republican nominee, Clinton campaign attorney Marc Elias hired Fusion GPS to investigate Trump on behalf of the 2016 Hillary Clinton presidential campaign and the Democratic National Committee. Fusion GPS later subcontracted Steele to research and compile the dossier. Following Trump's election as president, funding from Clinton and the Democrats ceased. Steele continued to work on the dossier, with financing reportedly coming directly from Glenn R. Simpson, co-founder of Fusion GPS. The completed dossier and its information was then passed on to British and American intelligence services.
Some of the dossier's allegations have been confirmed, while others have yet to be proved or disproved. Some claims may require access to classified information for verification. The media, intelligence community, as well as most experts have treated the dossier with caution, while Trump himself denounced the report as "fake news". In February 2017, some details related to conversations "solely between foreign nationals" were independently verified. Some of those individuals were known to be "heavily involved" in efforts to damage Clinton and help Trump. The conversations "took place between the same individuals on the same days and from the same locations as detailed in the dossier", giving "US intelligence and law enforcement 'greater confidence' in the credibility of some aspects of the dossier as they continue to actively investigate its contents".