Documents released by the US Department of Justice on Saturday indicated that a top advisor to then-candidate Donald Trump said as early as the summer of 2016 that Ukraine, not Russia, was behind a hack of Democratic party emails.
Trump and his surrogates have suggested that Kiev hacked Democratic National Committee servers and planted evidence to frame Russia, as a way of undermining the legitimacy of the US leader's election.
Trump has pressured Ukraine's president to investigate that debunked conspiracy theory as well as his election rival Joe Biden -- a move at the crux of an impeachment investigation against him in the House of Representatives.
The hundreds of pages of documents out Saturday were part of an initial tranche released to US media outlets Buzzfeed and CNN, which sued the government for access to notes from the investigation conducted by special counsel Robert Mueller into Russian meddling in the 2016 election.
Installments of the internal documents from the Mueller probe, which concluded in March, will be released every month for the next eight years, Buzzfeed said.
Campaign chairman Paul Manafort spread the theory among his aides that Ukraine -- not Russia -- had hacked the Democratic National Committee, deputy campaign manager Rick Gates told the FBI, according to a heavily redacted summary of an interview conducted by the agency.
In July 2016, WikiLeaks began publishing thousands of Democratic National Committee emails, embarrassing Trump's election rival Hillary Clinton. US intelligence later said that the emails were hacked by Russian spies and handed over to WikiLeaks.
The documents released Saturday also showed how Trump, his top aides and family members repeatedly discussed how to get the hacked Democratic emails that WikiLeaks had obtained.