Thieves who stripped stone flags from a historic Bradford museum have been accused of “cultural vandalism” by a senior councillor.

Up to two tonnes of stone, valued at £6,000, has been stolen from the Grade I listed Bolling Hall, leaving museum officials heartbroken.

Councillor Dave Green, Bradford Council’s executive member responsible for culture, condemned the thieves for “stealing from the taxpayers in the district”.

He said: “They are damaging the heritage of the city. I would urge anybody who has any information to contact the police so we can ensure that any future acts of theft are deterred.”

CCTV captured footage of a three-and-a-half-ton lorry being driven into the museum grounds after the lock on the gates was cut off. The truck was used to carry away the expensive Yorkshire Stone.

David McIlroy, visitor services supervisor for Bradford East, said that it was the worst case of theft he had seen in his six years at the museum, parts of which date back to medieval times.

He discovered it when he arrived for work to find holes in the main courtyard grounds.

“It has gone from petty theft to industrial theft,” Mr McIlroy said.

“It is heartbreaking. It is not only damaging council property but it does not look good for the people of Bradford to come and see it in such a state.

“We now have extra CCTV and we are looking at alternative ways to stop this theft occurring or replace the stone so it can’t be stolen. Yorkshire Stone is so expensive.”

An English Heritage spokesman said it was increasingly seeing more instances of heritage crime, from lead theft from church roofs to vandalism and damage to historic monuments.

“Bolling Hall Museum is a Grade I listed building and grade I buildings are of exceptional interest,” the spokesman said. “They are sometimes considered to be internationally important. Only 2.5 per cent of listed buildings are at this grade.”

Police have confirmed they are examining CCTV footage to find the thieves and urged witnesses to call them. The truck was captured on CCTV being driven into the grounds at 9.40pm on Wednesday, according to museum staff.

Sergeant David Shaw, of the East Bowling, Barkerend and Bradford Moor Neighbourhood Policing Team, said lifting equipment would also have been needed to remove the stone.

He said: “This will not have been a quick task to undertake. I am sure that passers-by in the area would have seen this happening and may be able to recall it occurring.

“I would call upon builders or stone merchants to be aware and if you are offered stone of this nature and are suspicious in any way contact us.

“Such thefts, particularly from public buildings, are not only disruptive to the staff and visitors who use them, but also damaging to the local heritage.

“If you can help us in our investigations, please contact Bradford South Police on the non emergency number 101 or Crimestoppers in confidence on 0800 555 111.”