Russia's communications oversight agency is moving to block access to an investigation published online by opposition leader Alexei Navalny alleging that Deputy Prime Minister Sergei Prikhodko received lavish hospitality from billionaire Oleg Deripaska.

The tycoon has been linked to President Donald Trump's former campaign chairman Paul Manafort.

The agency, Roskomnadzor, said Saturday it has placed the investigation, which was published Thursday on the website of Navalny's Anti-Corruption Foundation, and a Youtube video of it, on its register of sites containing information not to be distributed in Russia, according to Russian news agencies.

The sites have three days after the notification to remove the material before being blocked.

Foundation lawyer Ivan Zhdanov says the move against the corruption report would be appealed in court.