Russian prosecutors have warned against sharing online any information from protest leader and blogger Alexei Navalny, who is under house arrest and banned from using the Internet, his supporters said Tuesday.
Navalny, whose popular blog and Twitter feed have been instrumental in the protest movement against President Vladimir Putin, was put under house arrest in February in an embezzlement probe and denied Internet access.
But his supporters have continued writing his Live Journal blog and tweets on his behalf -- which rankles Russian authorities.
In a letter published on Navalny's blog, allegedly to a Russian Internet provider, the Moscow prosecutors complain that "groups connected with (Navalny) continue publishing information in his name."
The prosecutors' letter did not identify the people but said it was a violation of house arrest rules, particularly because the messages posted online urge Russians to attend protest rallies.
"The publications... contain calls to participate in mass public actions in violation of public order," said the letter, adding that Navalny's pages on Facebook, Russia's main social networking site VKontakte, Twitter, and Live Journal "form the readers' opinion."
Vedomosti business daily reported that similar letters were sent out to the companies that control Russian social networking sites.
Company representatives told Vedomosti they were not taking any action since the warning letters did not give any specific instructions.
Last month Russia's media watchdog blocked three major opposition websites for republishing Navalny's blog, a fiercely critical outlet that was paramount in the mass protests in 2011-12 and that Navalny used to campaign for Moscow mayor last year, coming in second place.
In February a Moscow court ordered the opposition politician under house arrest and banned him from communicating except to lawyers or family in what he said was yet another attempt to silence him.
Navalny -- who was last year given a suspended five-year sentence in a separate timber embezzlement case -- faces charges along with his brother Oleg of stealing and laundering a total of 51 million rubles ($1.4 million) from cosmetics company Yves Rocher and a Russian firm.
His supporters and wife Yulia Navalnaya have said that Navalny's blog is now updated by them.