It also ordered Mr. Navalny’s Anti-Corruption Foundation to remove the text of the investigation and ordered YouTube to remove Mr. Navalny’s video.
As of Monday, the video was still accessible in Russia, and had been viewed more than four million times. It has also been generously covered by various independent Russian media outlets.
YouTube has not decided how to respond to the legal notice, according to a person who was granted anonymity to discuss the company’s thinking. YouTube has informed the uploader of the legal notice, but has not told it to take it down, this person said, adding that if YouTube were to comply, it would not take down the video from YouTube globally, but block it only on the Russian YouTube site.
An Instagram representative did not immediately respond to a request for comment.
A representative of Mr. Deripaska accused the companies of conspiring in a bid to promote Ms. Vashukevich’s book.
“The media seized upon Navalny’s information attack and began illegally republishing private photographs,” the business publication Vedomosti quoted the representative as saying.
The agency also instructed six Russian-language news outlets to delete or redact articles relating to the Navalny investigation, and at least two have complied.
A court injunction of this sort against content hosted on Instagram and YouTube is unprecedented for Russia, an agency representative told Vedomosti.
The tactic may signal a more aggressive approach by the Russian government in its bid to rein in social media and video-sharing websites popular in the country. Since not all internet service providers in Russia are able to cut access to individual web pages, they may be forced to block YouTube and Instagram if the companies fail to comply with the Roskomnadzor order.
On Monday, Mr. Navalny said that both the court and the agency were doing the bidding of Mr. Prikhodko and Mr. Deripaska. “It turns out that the oligarch Deripaska has not only a pocket court but a whole pocket town,” he said.
Mr. Navalny linked the attempt to block his website with his campaign to boycott the presidential election on March 18, which Mr. Navalny was barred from running in. He called for his viewers to help give his latest corruption investigation the widest exposure.
“It wasn’t me who sailed on a yacht, it wasn’t me who hired prostitutes for fun, it wasn’t me who took bribes from an oligarch in the form of airplane flights and expensive cruises,” he said on Monday, “but the singular, lightning-fast attack of the government is directed against me and my foundation, who exposed the corruption. This is a war of our dissemination against their blockage. And it’s one we have to win.”