Police are treating Thursday’s fire at the former British Sugar Sport and Social club in Spalding as arson.
They say the building, which was derelict and described as unsafe to enter, was deliberately set alight.
It will now have to be destroyed, at a value of £40,000.
PC Claire Riches, of Community Policing in Spalding, said: “This is a high value arson. Someone in the community will have knowledge of who set this fire. Please help us find the offender.”
Anyone with information that will help the enquiry is asked to contact PC Claire Riches on the non-emergency number 101. The charity Crimestoppers can also be contacted, anonymously, on 0800 555111.
Reference: Incident 242 of March 24.