A flagship office block will rise from the ashes of a Victorian mill which was destroyed in a huge blaze.

Fire investigators believe the inferno which engulfed the mill building in Harris Street, Barkerend, Bradford, was probably started deliberately.

But they admitted today they may never know what started the blaze and police are to take no further action.

The building, which belonged to one of Bradford's biggest textile companies, Dilbag Cloth House Limited, had to be demolished following the fire but the owners today pledged to press ahead with plans to build an office complex on the site.

Bobby Singh, son of Baildon millionaire Dilbag Singh, said the building was empty and due for demolition to make way for a flagship office complex.

The building had been uninsured but Mr Singh said the office scheme would be unaffected by the fire and would continue as planned in September.

"It doesn't make a difference to us that they have not found out who's done it," he said. "We were going to demolish the building anyway."

Sixty fire-fighters tackled the blaze on Saturday, July 17, and prevented the fire from spreading to nearby buildings close to historic Little Germany.

But the mill collapsed and had to be completely demolished the next day.

A spokesman for the fire service said that investigations into how the fire started had been inconclusive.

But he said that it had 'most probably' been started deliberately.

"Because it got in such a state and collapsed there was not a lot of opportunity to investigate," he said.

"From what they can see the most probable cause is that it was deliberate, but it is almost impossible to find out how it started."

West Yorkshire Police confirmed that, as the cause of the fire has been recorded as unknown, there was no evidence to suggest criminal activity, and they would be taking no further action.