More detailed investigations into the cause of a fire at a disused mill in Bradford city centre are under way after demolition work on the building was completed.

Police and fire investigation officers were yesterday carrying out further inquiries at the site of Thompson Mill, after it was made secure when the building was pulled down on Wednesday night.

Detectives, who believe the fire may have been started deliberately, have also issued a fresh appeal for witnesses or anyone with information to come forward.

Detective Inspector Nicola Bryar, of Bradford South CID, said: “Information from the fire investigators at the site suggest this fire may have been malicious.

“We would therefore like to hear from anyone who has seen suspicious activity in or around the area of the mill on the night this fire took hold.

“Likewise, if you have any information which could help further our investigations, we would like to speak to you.”

Demolition workers from Thomas Crompton Ltd spent Wednesday evening pulling down the building, which had been left unsafe after the fire destroyed all five floors, and was swaying in gusts of wind.

Thomas Crompton, who runs the plant hire, demolition and waste company, in Neville Road, Bradford, yesterday told the Telegraph & Argus how the firm made the site safe for officers to begin formal investigations.

He said: “We had to make sure it came down in a controlled manner and not collapse.

“We got a bit worried after 7pm on Wednesday night when the wind started to build up, but fortunately it just held off long enough for us to get it down safely.

“We will be here for four weeks on site cleaning up and sorting it out.

“We could see part of it swaying in the wind so there was a danger because there are a couple of buildings nearby.

“We have had meetings with the fire investigators and the police today and they will be conducting their inquiries throughout the day.

“We have done the demolition in such a way so that they can get in.”

Mr Crompton said Thompson Mill was the third mill his company had had to pull down in about three years within a mile radius of the site.

Witnesses or anyone who has any information about the blaze on Tuesday night has been asked to contact Bradford South CID on 0845 6060606 or Crimestoppers, in confidence, on 0800 555 111.