Arson has not been ruled out as the cause of the fire that destroyed the "entire history" of the company behind the Wallace and Gromit films, fire chiefs have revealed.

But it may be some weeks before fire investigators can determine what started the blaze at Aardman Animation's warehouse, Bristol, as structural damage meant they could not enter until yesterday.

Wallace and Gromit creator Nick Park, who grew up in Walton-le-Dale, said the fire on Tuesday was "dreadful" news for the company but comparatively "not a big deal".

Aardman spokesman Arthur Sheriff said: "Everything has gone, from as far back as Morph and all the way through to Chicken Run, including all the Wallace and Gromit films and Creature Comforts. Everyone is devastated."

The news came as company bosses discovered the new Wallace and Gromit film, the Curse of the Were-Rabbit, had gone in at number one at the US box office. The film goes on general release in Britain tomorrow.

Aardman Animations was formed in Bristol in 1976 and claimed its first success a year later when Morph was launched on the BBC and quickly established himself as a children's favourite.

Nick Park, a former pupil of St Cuthbert Mayne High, now Our Lady's, in Fulwood, joined the company in 1985.

Five years later he won an Oscar for the Creature Comforts, and went on to win two more for Wallace and Gromit's The Wrong Trousers and A Close Shave.

The company has gone on to produce everything from pop videos to advertisements, short films to feature-length movies.