Mr Searle, the reclusive creator of the St Trinians tales about schoolgirl minxes, was dismissive of the movie's suggestion that the prisoners of war who built the track saw it as a matter of British pride.
The film won seven Oscars for its portrayal of the brutal conditions under which their Japanese masters kept the Allied prisoners as they forced them to build the death railway. Director Sir David Lean based the popular 1957 movie on a novel by Pierre Boulle, which also comes in for criticism in Searle's attack which will be broadcast today in Radio 4's Desert Island Discs.
"It is nonsense and absolute rubbish. It is a romantic novel, a Frenchman's idea of how the British behave. A sort of "jolly good chaps and let's build a bridge," Mr Searle said in his first broadcast interview for three decades.
The humorist said that the railway was seen rather as a source of national shame with British officers assigning any troublemakers in their number to keep them out of the way, The Sunday Telegraph reports.
Mr Searle began work on the railway in 1943 after he and two other prisoners began producing a magazine to keep up the PoWs' morale. "It upset the extremely conservative mentalities of our own administration - the commanders and the chaplains. When the time came for the Japanese to say we want groups to be sent up north, the English chose the troublemakers," he said.
The interview with Mr Searle, which was conducted in France where he now lives instead of the more usual recording at the BBC's Broadcasting House, is timed to mark the 60th anniversary of the end of the Second World War. In it, he gives his account of their appalling existence as prisoners and talks about how his own weight plunged to just six stones. "We were dirt," he said.
Searle, who was also co-author of the Molesworth series, said that the experience coloured his career: "The horror, the misery, the blackness changed the attitude to all things, including humour."