Russia has threatened to block Facebook as the authorities attempt to extend their control of the Internet and shut down the encrypted messaging service Telegram.

Alexander Zharov, the head of the state communications oversight agency Roskomnadzor, said it would conduct a check of Facebook in 2018 to see whether it is storing Russians' personal data on servers in the country, as is stipulated under a controversial 2014 law.

It would also make sure the US Internet giant is deleting information banned by the Russian authorities, noting that “they are being significantly late” to do so.

“If all or some of these things are not implemented or the Russian government is not informed of intentions to take these actions, then the issue of a block will obviously arise,” Mr Zharov told the newspaper Izvestia.

Mr Zharov said he had “expressed our position” to Facebook at a February meeting.