A video accusing Russian Prime Minister Dmitry Medvedev of corruption was published on two government websites on June 11, one day ahead of planned nationwide anticorruption protests organized by opposition leader Aleksei Navalny.
The video, produced by Navalny and his supporters, was published on the websites of the regional prosecutor's office in the central city of Yaroslavl and the St. Petersburg regional administration.
Later in the day, the video was removed from the St. Petersburg administration's website, while the Yaroslavl prosecutors' site was down.
Russian media reports said Yaroslavl prosecutors suspect hackers were behind the incident. There was no immediate public comment from the St. Petersburg administration.
Archived versions of both pages featuring the video remained accessible.
The video, which has garnered more than 22 million views on YouTube since it was released in March, accuses Medvedev of using a network of purported charitable foundations to control wealth both in Russia and abroad.
Medvedev has called the allegations "false statements of political adventurers."
The Kremlin has brushed off the investigation, which helped galvanize tens of thousands of protesters in cities across Russia on March 26 -- the biggest grassroots rallies in the country since a series of demonstrations more than five years ago.
Navalny, who is seeking to run for president next year, is spearheading another round of nationwide anticorruption protests planned in more than 100 cities on June 12.
With reporting by RFE/RL's Russian Service and Kommersant