Career
He was quickly spotted by the British security services who gave him the codename "Pogo" and used one of their double-agents to feed him disinformation which was relayed to the Germans. Born in Santa Cruz de Tenerife on 21 May 1916, Piernavieja del Pozo was a Falangist who had worked for Franco during the In 1940, the British Embassy in Madrid, with the personal recommendation of British ambassador Samuel Hoare, arranged for Piernavieja del Pozo to travel to Britain as an observer for a Madrid based study group. He arrived in Britain on 29 September 1940.
Piernavieja del Pozo was contacted by Gwylm Williams, who had tried to work for the Germans in 1939 but had been recruited as a double-agent by MI5 instead.
Williams posed as an ardent Welsh nationalist and Piernavieja del Pozo gave him £3900 (a sum more than 10x the average annual wage) in a talcum-powder tin and asked him to obtain information on the Welsh nationalist movement and on factories making munitions in the west of England. According to Williams, Pozo had asked him to make plans for sabotage.
He returned to Spain in January 1941.