The social media platform Telegram uses an algorithm that promotes extremist content, a new study shared exclusively with the BBC has revealed.

Axar.az report that from the US civil rights organisation the Southern Poverty Law Center (SPLC), found that the "similar channels" feature introduced last year recommends extremist channels even to users browsing subjects such as celebrities or technology.

A professor also showed BBC Panorama how he found someone within moments on Telegram who offered to ship an Uzi submachine gun to the UK for £850.

Telegram says users are "only presented with content they have chosen to engage with" and it removes millions of pieces of harmful content daily.

The company's founder, Russian billionaire Pavel Durov, is under formal investigation in France accused of failing to stop criminality on his platform. He has denied the allegations.

Best known as a messaging app marketed with secretive features, Telegram also allows its almost one billion users to set up channels where they can broadcast messages and videos to up to 200,000 people at a time.