A police chief told of the chaos caused when a fathers' rights protester scaled a crane dressed as Spider-Man.

Police had to seal off the area around Tower Bridge when David Chick, 36, of The Ridgeway, Burgess Hill, was seen wandering along the arm of the 145ft structure with no safety harness.

Chick climbed to the top of the crane in his superhero outfit, Southwark Crown Court heard.

Months earlier, he had carried out a similar protest in the outfit, also on a building site near London's Tower Bridge.

Superintendent Richard Walker, who led day-time police operations during the later stunt, said he decided to shut off the area. Chick could have fallen at any time and posed a risk to members of the public below the crane in St Katherine's Way.

Mr Walker called on his experience of the previous protest, in June last year, when the crane had swung round, causing further concerns about public safety.

He said: "He was coming out of the cab and walking across the crane. I saw him get right to the very end.

"He seemed to be doing some sort of stretching.

"At one point I saw him standing on top of the crane."

Police sealed off the area after watching Chick cross the crane at a great height.

Mr Walker said: "I saw him walk across the gantry. At one point I saw him walk right to the very end. There was no harness or safety equipment visible.

"My primary concern was for public safety."

During the six-day protest, a specialist team of 15 officers were called in to coax Chick from the crane.

But he refused to come down for almost a week between October 31 and November 5, bringing traffic to a standstill, damaging traders' businesses and inconveniencing the public.

Chick had mounted the crane to unfurl banners of the Fathers for Justice group, despite not belonging to it.

Two members of the organisation had previously climbed on to the roof of the High Court in central London dressed as the Caped Crusader and his sidekick the Boy Blunder.

They were drawing attention to their campaign for the better treatment of single fathers by the courts.

Chick denies causing a public nuisance between 30 October and 6 November, 2003.

The trial continues.