A Nazi submarine mission to the United States during World War II turned into a story worthy of a comedy film after being hit by a series of blunders, both accidental and deliberate, as newly-released files from Britain's MI5 domestic intelligence agency reveal.
In June 1942, the Germans planned to bomb roads, railways and factories during Operation Pastorius, but even before it got under way the expedition descended into farce.
One of the saboteurs, Herbert Haupt, got drunk in a Paris bar after a farewell dinner and declared to his drinking companions that he was a spy.
When the submarine arrived on the coast of Long Island, New York, to drop off the four agents, it ran aground on a sandbar.
A US coastguard discovered the Germans as they buried their supplies on the beach - but he was given $300 and persuaded to leave them alone.
The plot was only foiled when the leader of the spies, George Dasch, rang up the FBI, announced he was a saboteur and demanded to speak to the bureau's then-director, J Edgar Hoover.
His confession was initially dismissed as a hoax, but after a lengthy interview he was arrested and his fellow agents were rounded up, the files show.
Despite the clumsiness of the mission, MI5 still regarded it as a serious threat. "This sabotage expedition was better equipped with sabotage apparatus and better trained than any other expeditions of which the security service has heard," wrote Victor Rothschild, head of MI5's counter-espionage division.
In 1943 a black and white propaganda movie, Operation Pastorius, was made of the farcical venture.