Organisers of the annual Antepavilion architecture charity competition have released footage of police storming their building and arresting staff ahead of the opening of the rooftop tensegrity structure targeted in the raid.
CCTV footage shows more than 40 officers streaming into the canalside Hoxton Docks arts building in east London after the door was forced open with power tools.
Another clip shows eight officers pulling owner Russell Gray off his motorbike when he arrived at the building after being told about the raid. A third clip shows police pushing Gray against a shutter and handcuffing him.
Gray, who heads the Antepavilion charity and owns the building it is based in, was arrested on suspicion of attempted assault and dangerous driving. He and two employees spent a night in jail but were released the next morning.
It is thought that police believed the building was being used by environmental protest group Extinction Rebellion to prepare for protests against media groups that are dismissive of climate change.