Tools, lights and workwear were taken from the former Carshock building on Skippers Lane, Middlesbrough.

The gear was being used by specialist contractors removing brown asbestos - one of the most dangerous forms of the material - from the premises.

A red letter “A” is marked on the stolen items, said Cleveland Police.

A force spokesman said: “Anyone who comes into contact with this equipment should contact us immediately, anonymously if necessary.

“We need to return the items to those properly equipped to handle them as they could cause serious damage to someone’s health.”

Anyone with information about the theft, which took place early on Friday, should contact police.