Intelligence officials with the FSB Federal Security service had repeatedly demanded that Telegram hand over its encryption keys, which would have allowed them to view messages stored in encrypted chats between users.
Russia's ban on encrypted messaging app Telegram has come into force, as the country's communication watchdog has given internet and mobile service providers 24 hours to block access to the app.
An estimated 9.5 million of Telegram's 200 million global users live in Russian Federation. Telegram's top officials said that this requirement was impossible to meet technically and tried to challenge it in several court battles, but to no avail.
A Russian government agency said on Monday that it had sent a notice to telecommunications providers to block Telegram. A Russian court has determined that security weighs heavier than liberty in a case that pitted social media giant Telegram against the Russian powers, which, Telegram, for now, has lost.
As expected, messaging app Telegram has been formally blocked in Russian Federation after its owner refused to hand the authorities encryption keys to help with investigations.
Writing on Vkontakte, the social media platform Durov founded that is now under state control, he said the decision harms Russia's national security as users will switch to WhatsApp and Facebook which are "controlled from the U.S.".
The messaging app is widely used across Russian Federation and many nations in the Middle East, as well as around the rest of the world.
As well as being popular with journalists and members of Russia's political opposition, Telegram is also used by the Kremlin to communicate with reporters and arrange regular conference calls with President Vladimir Putin's spokesman. Reportedly, government officials access the app via a VPN - a technique commonly used in Russian Federation to circumvent internet restrictions - to communicate with the media and coordinate timing for conference calls. But on Monday, the Russian Federation spokesman's office said it will now start using a different app.