Intruders climbing onto the roofs of city centre properties are risking their lives and causing thousands of pounds worth of damage to historic buildings, say witnesses.

The alarm has been raised by the boss of a building firm who shot a video of a young man playing about atop the former Nasons store site in Canterbury.

Man on top of Nasons roof in Canterbury

Graham Cowderoy, who runs Hartley Developments, witnessed and filmed the worrying scene on his mobile phone around noon on Monday as he worked on the roof of a nearby property.

"He was just climbing around and sliding about damaging slates and it looked pretty dangerous too," he said.

The footage shows the man, wearing a face mask, walking along the roof top before resting perilously close to the edge.

Mr Cowderoy says he is aware of numerous similar incidents, including on the roof of the Cuban bar, and been asked to make repairs.

He also says that valuable leadwork has been ripped up from some properties.

"I reckon there's been at least £6,000 worth of damage and the police have been called in the past but I don't think there's a lot they can do," he said.

"But sooner or later, someone is going to fall and get seriously injured or even killed."

Mr Cowderoy says there are numerous ways people can get onto roofs in the city centre, including using flat roofs to scale the buildings, making it difficult to deter.

Karl Elliott of architects Clague which has been closely involved in the redevelopment scheme for Nasons, says the company is aware of the problem.

"It's obviously trespass and also a very dangerous thing to do," he said.

"There is on-site security but not a lot anyone can safely do when people are up on the roof.

"We are also aware there has been some damage, including to a high speed BT broad band cable which was on the flat roof at Nasons."

Canterbury BID boss, Lisa Carlson added: "We are aware of the vandalism taking place on the roofs of city centre businesses, and the detrimental impact that this has.

"We are doing everything we can to help businesses to report these issues and we are working with the Community Safety Unit to help find a solution."