Persistent thieves are believed to have returned several times to steal lead from the roof of a popular attraction.
Police are investigating after The Canterbury Tales, in St Margaret's Street in Canterbury, had about 20 metres of the heavy metal swiped - despite the building being close to a busy high street.
Brothers John and Derek Richards, both contractors for The Canterbury Tales, believe the thieves climbed onto the roof of Nasons - which closed last year - and scurried across to their target.
"They would have done this over a few days with the vast amount of roof which has been stripped - there is only so much of this lead you can carry at a time," John said.
"It could have been going on for weeks but we just don't know. They must be desperate.
"They must have had a truck because lead is so heavy.
"Five metres of lead is enough for one person to carry."
A window was also found to be smashed on the former Nasons building which is adjacent to The Canterbury Tales.
The Canterbury Tales Operations Duty Manager Luke Ludlam said: "We were saddened to discover that a section of our lead roof was stolen.
"If anyone saw anything suspicious on Wednesday evening or has any information in connection with the burglary, please contact Kent Police."
Police received a report of theft of lead from the roof of a building in St Margaret’s Street, Canterbury.
It is not yet known when the theft may have occurred but officers received the report on Wednesday.
Anyone with information should call police on 01843 222289 quoting reference 46/203965/19