Gibraltar was a nest of espionage activity in June, 1943, as rumour spread that the Rock was about to be used as Allied headquarters for the invasion of North Africa. The Germans, aware of the Allied intentions, planned to frustrate them by using Spanish agents to blow up the place with explosives hidden in the network of caves under it.
Gibraltar Police heard about the German plot when a local Gibraltarian told them: I have been approached by a Spaniard, Luis Cordon-Guenca, whos threatened to kill my wife if I dont plant the bombs.
The police told the local man to obey the Spaniards instructions, and to keep them informed. A week later, on June 23rd, he reported to the police that the bomb plot was ready to proceed.
In classic spy story style, the Spaniard Cordon-Guenca met the Gibraltarian in a park to hand over a bomb detonator, hidden in a fountain pen. As they talked, armed Gibraltar Police and MI5 officers emerged from hiding and pounced on the Spaniard. Detectives later found explosives at a shop where he worked.
A week after Cordon-Guenca was arrested a bomb exploded in the naval yard at Coaling Island. MI5 officers kept one worker, Jos? Martin Munez, 19, under surveillance, noting that he was keeping company with prostitutes and that he was spending much more money than a part-time worker at the yard could earn.
Munez was questioned and admitted planting the bomb. He said he enjoyed the excitement of sabotage, and he didnt like the British anyway.
Both Cordon-Guenca, 23, and Munez were hanged in Gibraltar Castle on Tuesday, January 11th, 1944. The Gibraltan who helped police arrest Cordon-Guenca was awarded the British Empire Medal.