By Polina Devitt and Denis Pinchuk
MOSCOW (Reuters) - Russian authorities blocked opposition leader Alexei Navalny's website on Thursday a month before a presidential election, a move Navalny said was designed to blunt his campaign for a boycott of what he says is a sham vote.
Roskomnadzor, Russia's communications regulator, said it had ordered telecoms operators to block parts of Navalny's site because he had ignored a request to remove material covered in an injunction obtained by Russian billionaire Oleg Deripaska.
Deripaska said his claim was related to the dissemination of false allegations about him based on leaked private information and was designed to protect his right to privacy.
"(It) has nothing to do with any political struggle between Mr Navalny and his political opponents," Deripaska said in a statement.
"Mr Navalny is not a party to the pending case as he was not the primary source of the leaked private information."
Navalny, who has been barred from running in the March 18 presidential election which incumbent Vladimir Putin is forecast to win, accused the authorities of acting to hinder his campaign aimed at getting people to boycott the election.
They had also wanted to help Deripaska remove information about himself from the public domain, Navalny said, saying he had no intention of voluntarily taking down the material.
The material is part of an investigation Navalny conducted, which alleged that Deripaska met Sergei Prikhodko, Russia's deputy prime minister, on a yacht belonging to the businessman off the coast of Norway in 2016.
Navalny questioned the ethics of the meeting in which he said the two men discussed U.S.-Russian relations, and he posted what purported to be photographs of the encounter taken from the social media account of a young woman who was also on the boat.
He also issued a YouTube video to accompany his investigation that has been watched over 5 million times.
Roskomnadzor, Russia's communications regulator, said Instagram had complied with a request to take down related material and that it was waiting for Google to delete Navalny's YouTube video.
Deripaska, in a statement last week, accused Navalny and others of spreading lies that he had allegedly committed unlawful actions and obtained an injunction from a court in southern Russia requiring media outlets to stop disseminating the disputed content.
Navalny's website was inaccessible inside Russia for much of the day, though a Navalny ally, Leonid Volkov, said on social media later on Thursday that it was available again via certain Internet providers.
(Writing by Andrew Osborn; Editing by Matthew Mpoke Bigg)