The lost originals include The Lavender Hill Mob, Whisky Galore and Passport to Pimlico. The original soundtrack to The Man in a White Suit has also been lost, though the negative was saved.
The negative of Kind Hearts and Coronets was saved just before an explosion of nitrate sent a fireball through Henderson's Film Laboratories in south London. About 25 other original negatives of British films from the Forties and Fifties are also understood to have been destroyed, though none as famous as the Ealing comedies.
The owner of the Ealing comedies, Lumiere Pictures, was at pains to point out last night that the public will not suffer as there are back-up negatives from which future prints can be made.
The company said, however, that the loss was still tragic because they had such sentimental value and were part of movie heritage. Martin Bingham, head of technical operations at Lumiere, said: 'There is back-up material but it is one generation away and some of it may have to be cleaned or double checked before future prints are made.
'Technically speaking, these originals were the best quality material.
'Because prints of the Ealing comedies are so often used they get scratched and the idea for the Barbican Festival was to make perfect, mint condition prints from the originals.
'What has happened is a terrible tragedy for sentimental reasons. But we have sufficient back-up material and the public won't notice a difference in the long term.'