A fierce fire that caused severe damage to a Bradford food store started in the roof of the building, it was revealed today.

Fire investigators who are probing the cause of the blaze at the Co-op, in Duckworth Lane, Heaton, have discovered that the blaze began in a void.

A fire service spokesman said the fire was not suspicious.

The building had closed for the night and was well-secured when the fire broke out, ruling out the possibility that it could have been started by an intruder.

However, the exact cause of the fire remains unclear and investigations are continuing.

Representatives of the Co-op were at the scene yesterday to carry out a full damage assessment.

A Co-op spokesman said the store would reopen “as soon as possible”, but added that it was too early to say how long it would take.

The spokesman said: “We don’t know how long it will take yet. They are still looking over the store.

“The shop floor areas got away with it. The main damage is in the back-room area.”

At the height of the blaze, which started at about 10.30pm on Friday, a total of 80 firefighters were at the scene tackling the flames.

Firefighters from Fairweather Green were the first to arrive and were soon joined by colleagues from at least eight other stations, including from as far afield as Castleford and Leeds.

The worst-hit area was at the back of the premises where offices, toilets and back-up refrigerators are located.

Although the fire did not affect the main food court area, it is thought likely that much of the stock within the store will have to be thrown away due to smoke damage.

The store had only been refurbished and relaunched a few months earlier.

The quick work of firefighters prevented the blaze from spreading to an adjoining takeaway food shop and a church hall.