Around �30,000 of damage was caused to the Grade II listed sports pavilion at Uppingham School.

Police believe the thatched building in Glaston Road was broken into in the early hours of November 11 and a fire started in one of the rooms.

The fire was brought under control but caused extensive heat and smoke damage to the pavilion.

Forensic evidence

Leicestershire police are offering the reward for information leading to the arrest and conviction of those responsible.

Area beat officer PC Adam Ploszczanski said: "This is a serious crime that has caused a huge amount of damage to a historical building.

"We have been following several lines of enquiry and have some good forensic evidence from the scene.

A substantial reward is now being offered in the hope that it will prompt people to come forward."

The fire was spotted by a passing patrol car at around 1.25am.

The sports pavilion at the independent boarding school was built shortly after World War One.