Firefighters are still combing through the rubble of a mill fire to determine whether the building was set alight deliberately.

The empty section of Dalton Mills, a Grade II listed building in Dalton Lane, Keighley, was gutted when engulfed by fire on New Year’s day.

Fire investigators already suspect there may have been people inside the building before the outbreak.

The 100 firefighters who tackled the blaze managed to stop it spreading to the occupied section of the mill and to nearby Burgess Ford, where some vehicles were damaged.

A spokesman for Airedale and North Bradford police said: “Investigations are still ongoing with the fire service and the relevant insurers to determine whether it was deliberate.”

At the height of the blaze, part of the building’s roof collapsed.

So far, there is no conclusion to the investigation which is still continuing, said a fire service spokesman.