The government of Ukraine imposed a ban on the Telegram messaging app being used on official devices belonging to government officials, military staff, and critical infrastructure workers, citing security fears.

In an announcement on Friday, Ukraine's National Security and Defence Council (Rnbo) claimed that Telegram posed a security threat to the nation, particularly during the war between Russia and Ukraine.

Kyrylo Budanov, Ukraine's Chief of Defence Intelligence, claimed he had "substantiated evidence" that Russia's intelligence agencies had access to the personal correspondence of Telegram's users (including deleted messages) as well as their private data.

"I have always stood for freedom of speech, but the issue of Telegram is not a matter of freedom of speech, it is a matter of national security," said Budanov.

The restrictions on using Telegram only appear applicable to official devices, not when the messaging app is used on personal phones.  Also, any officials whose work duties include the use of the app (such as those who maintain and update Ukraine's official Telegram pages) are exempt from the ban.

I presume that one person who will not be impacted by the ban is Ukrainian President Volodymyr Zelensky, who posts video addresses every day to his over 700,000 followers.

Responding to the news of the ban, Telegram issued a statement to the BBC saying that it had "never provided any messaging data to any country, including Russia."

The company claims that "deleted messages are deleted forever and are technically impossible to recover" and that "every instance of supposed 'leaked messages'... has been the result of a compromised device, whether through confiscation or malware."

Telegram says that it would welcome the chance to review "any evidence that supports Mr Budanov's claims."

Pavel Durov, the founder of Telegram, is currently facing charges in France related to alleged complicity in allowing organised criminal activities to flourish on the app.

Now, in an apparent attempt to appease the growing concern amongst law enforcement agencies about the level of crime taking place on Telegram, Durov has said that his company would disclose users' phones and IP addresses to authorities upon receiving valid legal requests.