Two so-called 'rooftoppers' have posted heart-stopping footage of their perilous climb to the top of One Canada Square, one of Canary Wharf's iconic buildings.

They posted an astonishing 10-and-a-half minute clip to YouTube, in which they manage to reach the top of London's second-tallest building.

The Canary Wharf Group, which owns the building, has said it is "working with the Metropolitan Police" after the security breach, and that it has tightened security provisions.

At the beginning of the clip, the camera man describes the climb as "almost impossible".

He said: “We are going to try to infiltrate the building called One Canada Square”.