A FIRE which caused damage estimated at £30m at ASOS's Grimethorpe clothing warehouse was 'more likely to be caused by someone working inside the building' than not according to a senior police officer.

Det Ch Insp Craig Jackson said items recovered in the aftermath of the fire were being forensically examined to try and identify one or more persons who may have been involved.

He said: "It is more likely than not that it was someone who was working in the building at the time. We are trying to use the forensic evidence to identify a person or persons who may be able to help with our enquiries.

"It is not a generally quick process but we are working with our forensic partners to understand the best strategy.

"I cannot comment on the items examined, only to say they are items recovered in the aftermath of the fire."

He said the forensic examinations would helpfully narrow down suspects from the 500 staff who were working in the building at the time.

Shortly after the fire in June, officers identified a particular box, out of about ten million, where it is thought the fire originated.