A CANNON shell discovered in sand dunes at a national trust site has been destroyed by bomb disposal experts.

Purbeck police captured footage of the controlled explosion on Knoll Beach in Studland.

A member of the National Trust discovered the cannon shell in the sand dunes at 1pm and called the police immediately.

Explosive and Ordinance Disposal officers were alerted and asked for a 50 to 75 metre cordon to be put in place.

At 3.38pm they arrived on scene and told police that they needed to explode the device.

Twenty minutes later they confirmed that it was live and increased the cordon to 100 metres.

It was destroyed at 4.17pm and the cordon lifted.