A HUGE blaze which destroyed a listed mill is being treated as arson, the police have said.

Prospect Mills in Thornton, which had been empty for years, had to be torn down after the fire ripped through the building on Thursday.

Investigators are now appealing for anyone who saw people acting suspiciously around the building to come forward.

A police spokesman said the fire service had confirmed the cause of the blaze was “malicious ignition”.

He said: “We are investigating it as arson.

“We would appeal to anyone who has seen anything suspicious, or who may have seen people acting suspiciously, to contact Bradford CID via 101.”