The cause of this month's Bridgehouse Mill fire in Haworth is still unknown.

Fire officers cannot carry out an in-depth investigation due to the dangerous state of the four-storey building.

They have gathered statements from witnesses and firefighters but cannot reach all parts of the mill.

Work on removing stones from the fire-ravaged top floor is expected to continue until at least the end of the month.

Building engineers will then be able to assess whether the remaining three storeys can be repaired or must be demolished. The March 5 fire raced through the top two storeys of the 200-year-old listed building within minutes of being discovered in a pile of rubbish.

A team of 60 firefighters managed to confine the blaze to the east wing, protecting major employer Wyedean Weaving and the Bridge House Hotel.

More than a dozen small businesses in the east wing were badly affected. Several moved into alternative premises this week.

Fire investigators believe the blaze started in the area where businessman Phil Booth, who alerted the fire brigade, tried to extinguish flames.

Station Officer Ian Purcell, the lead investigator, says it is not yet known whether the fire was accidental or deliberate. All avenues are being explored.

He says: "We can certainly rule out anything like smoking. We've got good witness reports from the people who discovered the fire."

Bront Foods, which has a factory behind the mill, is working closely with demolition contractors and building engineers to keep access open.

For the first few days the firm could drive only small delivery lorries through the archway beneath the mill to its premises.

David Shaw, the managing director, says permission was given last Friday for full-size articulated lorries to again drive through.

He praised the Keighley and Worth Valley Railway for letting employees use its car park, and thanked villagers for their understanding in putting up with extra cars in nearby streets.