Lara O'Reilly

The ad contains substances which are banned by the football league.

The move is unusual for a U.S.-based tech firm.

'He's constantly on Twitter, constantly talking about what they are doing -- and how he's feeling about it as well.'

Bryant has teamed up with tech entrepreneur and investor Jeff Stibel to launch Bryant Stibel, which will be based in Los Angeles.

Stories is a hugely-popular part of the Snapchat app, with more than a third of its daily users using the feature to broadcast what they getting up to.

Its popularity appears to have taken Snapchat by surprise.