A 2015 law requires internet companies to store Russian citizens’ personal data on local servers accessible to local law enforcement. Over the past year, the popular Telegram messaging app has been embroiled in a legal battle with Russia's Federal Security Services (FSB) over refusing to provide access to the online conversations of users, including suspected terrorists.

Messaging services in Russia have been banned from disclosing any cooperation with law enforcement agencies, according to a new government decree.

The new decree orders messengers to “ensure the non-disclosure of any information regarding specific facts and contents” when cooperating with the authorities.

The messengers are also required to provide remote access to their systems no later than three months after receiving a request from the FSB.

Last year, Telegram appealed to the UN to intervene in its legal battle with the FSB over online privacy rights. Telegram's founder, Pavel Durov, has previously said that the FSB's demands violate the constitutional rights of Russian citizens to the privacy of correspondence.