 In March 1943 an ammunition dump was blown up by Calvo 's agents . The British , growing suspicious of some of the saboteurs , banned them from entering Gibraltar . This forced the Abwehr to ask Calvo for new personnel . A Spaniard working on the Rock , José Martín Muñoz , was responsible for the explosion and fire at a large fuel tank at Coaling Island on 30 June 1943 ; this mission , however , would be the first and the last for Muñoz , because he was cornered and arrested by British authorities in August , when he tried to smuggle a bomb into a weapons magazine inside Ragged Staff Cave . After being sentenced to death , he was hanged on 11 January 1944 in Gibraltar by British executioner Albert Pierrepoint . A member of an unrelated Abwehr sabotage network , Luis López Cordón @-@ Cuenca ( also arrested in 1943 ) was executed by Pierrepoint on the same day . Calvo himself was put under arrest by the Spanish police and neutralized . He would be a free man again in December , when he rejoined the Abwehr in Madrid , under direct orders of Wolfgang <unk> , aka Baumann , head of the sabotage section in Spain . After a Falangist attempt against the life of pro @-@ allied General José Enrique Varela , perpetrated by Sánchez Rubio network 's agent Juan José Domínguez and a meeting between Anthony Eden and the Spanish ambassador at London , Jacobo Fitz @-@ James Stuart , Abwehr activities around Gibraltar came to an end . 
