ARSON cannot be ruled out as the cause of Thursday's fire at Hayle's indoor market which shut 20 on-site businesses.

Up to 70 firefighters from seven crews responded to last Thursday's 8am call to find smoke pouring through the roof of Pratt's Market.

Fire crews using breathing apparatus battled for five hours with difficult access and thick, black smoke before declaring control of the situation.

A statement from Cornwall Council said: "Investigations are on-going, with the police and fire services as they have been unable to rule out arson."

The blaze broke out in the rear left corner of the building and was contained to the area.

Incident commander, Steve Benney, said: "This was a very difficult fire to fight and there were a number of difficult issues. It was difficult to get into the building for a start, and we weren't sure what the stalls were inside, or what kind of fire it would be.

"Access was tricky because the hall is surrounded by houses and is quite tightly packed. Fortunately, the fire didn't break through and it was contained to the building."

Smoke filled the building, making visibility almost impossible – placing risks on fire-fighters as they were uncertain of what they were facing.

Group manager Dave King said: "The building was heavily smoke-logged. Fire crews inside would not have been able to see a thing."

Traders were left with no choice other than to shut up shop as they awaited reports of damage to the building and count the cost of fire-damaged stock.

Paul Dyer, who has three businesses in the market, said: "It's a lot better than we thought it would be. We have lost a considerable amount of stock and equipment but it could be quite a lot worse."

Mr Dyer, whose gallery, frame makers and home brew suppliers, operate from the building, said any structural damage would delay their re-opening.