In September 1940 Jose Walberg, a 22-year-old German, and two Dutchmen, Carl Heinrich Meier, 24, and Charles Albert van den Kielboom, 26, together with a third Dutchman named Pons, landed at night near Dungeness and Hythe on the south-east coast of England in two parties, each equipped with a wireless transmitter, food, maps, and large sums of cash. Their mission was to obtain and transmit military information, and they failed miserably.

Kielboom, Pons and Meier were captured separately within a few hours of landing. Walberg was arrested a day later, but not before he managed to rig up an aerial in a tree and send a worthless radio message to his Nazi masters.

Pons and Kielboom claimed they had been blackmailed into joining the Abwehr, the German secret service, and that they had not intended to do any spying. Kielboom said they had planned to go to America, while Pons claimed he had intended to give himself up. Meier told a similar story, saying he had been induced to join the Abwehr by the prospect of good remuneration. Walberg, unlike the others, was a professional spy, and he admitted receiving two years’ training in espionage.

All were charged under the Treachery Act which had come into force in 1940, and at their trial Walberg pleaded guilty; Meier and Kielboom were also convicted, and all three were sentenced to death. Pons, however, managed to convince the jury that he’d had no intention of acting against England, and he was acquitted and interned as an alien.

“We are not concerned with the reasons spies may put forward as having induced them to take service with the enemy, whether it is duress, blackmail or that they only came because they wanted to come here without any intention of spying at all,” a Home Office minister said at a meeting with the Secretary of State.

“These stories are only told after they are caught. If we were to accept excuses such as these men have put forward it would certainly assist the Gestapo in recruiting spies.”

And the Gestapo was clearly in need of assistance, the swift collaring of its would-be spies demonstrating the amateurishness of its early attempts at espionage which were almost farcical. Walberg could not speak a word of English, although he was fluent in French. Two of the Dutchmen had no more than a smattering of English, and one of them had binoculars and a spare pair of shoes slung around his neck when he was spotted by the astonished Somerset Light Infantry private who captured him.

The only one of the four with a fluent command of English came unstuck through his ignorance of Britain’s licensing laws. At a pub in Lydd, he tried to buy cider at breakfast-time. The landlady told him this could not be done legally until 10 a.m., and advised him meanwhile to take a look at the church. She was no fool, and on his return he was arrested.