Facebook has turned over all information about ads "likely" purchased by Russian operatives to special counsel Robert Mueller, according to a report.

A source familiar with the matter told Reuters on Wednesday that the social media giant had sent the former FBI director data including copies of the ads and the identity of the buyers. That report followed news that an internal Facebook investigation found it is agents of the Kremlin may have spent $100,000 on ads with "divisive messages" between June 2015 and May 2017.

A Facebook blog post published on Wednesday said the operation involved 3,000 separate ads over a two-year period and was likely to have been run out of Russia. In addition, Facebook found 470 affiliated fake accounts and pages.

Mueller is investigating Russian efforts to influence the 2016 election and whether the Trump campaign colluded with the Kremlin. The investigation has dogged and frustrated President Donald Trump, who has called it a "witch hunt" and a "hoax."