A hungry mouse may have sparked a massive blaze which wrecked a £2.2 million farmhouse owned by a leading leisure entrepreneur.

Chris Chapman, founder of the Chapman Group hotel and pub chain, said the damage to the tiled roof alone could be more than £100,000.

About 100 firefighters from all over West Sussex rushed to the blaze at Grade II listed Avenals Farm, off Water Lane, Angmering, near Worthing.

Mr Chapman, 55, his wife Delia, 50, and their son Shea, 15, fled in their nightclothes as flames lit up the village.

Their dogs, Harvey, a great dane, and Scruff, a westie, also escaped unharmed.

Mr Chapman said: “They reckon a mouse could have eaten into a cable and sparked it. We’d had the pest control people round recently and they found several mice in the loft.

“The fire investigation people are still working on it but they said mice were quite often the cause.”

A West Sussex Fire and Rescue spokeswoman said: “I cannot confirm anything at the moment because we have still got it under investigation. But mice are known as a cause of some fires.”

Mr Chapman, whose family has lived in the farmhouse for six years, said smoke detectors had saved their lives.

He believed they would have been trapped by the inferno had they gone to bed before discovering the flames.

The fire started at about 10.45pm on Thursday when Shea came screaming down the stairs saying the smoke alarms were going off and he couldn’t reset them.

Mr Chapman said firefighters believed the blaze had started in the loft of the farmhouse, part of which dated back to the 15th century, and must have been burning for a long time.

He said the heat was so intense the tiles on the roof were cracking.

Mr Chapman said: “If we had gone to bed, the fire would have trapped us in our bedrooms. We would have been goners. I would recommend to everyone to have smoke detectors installed.”

Fire crews from East Preston were first on the scene.

Six pumps arrived, a total which rapidly increased to 12 amid fears the fire would spread.