The head of a Russian propaganda campaign that allegedly aimed to influence the upcoming U.S. elections began as a liberal politician before he became one of President Vladimir Putin’s closest advisers.

Sergei Kiriyenko, who is the first deputy head in Putin’s administration, oversaw a yearslong Kremlin operation to meddle in U.S. elections and use disinformation to promote pro-Russian narratives online, according to a 277-page affidavit that U.S. officials unsealed Wednesday.

Kiriyenko, 62, participated in meetings in which Russian officials discussed ways to promote Donald Trump’s candidacy, undermine support for Ukraine and further Russian interests, according to the court filings. The plans manifested in an effort known as "Doppelganger,” which used domain names that impersonated established media outlets to present fake news as content that came from trusted sources.