I have been able to find little information on the destruction of HM Trawler Erin at Gibraltar on January 18, 1942, but here is what I was able to find. On that day several trawlers of the 7th A/S Group were in harbor at Gibraltar when a team of Spanish saboteurs, trained by the Abwehr, placed an explosive in HM Trawler Erin. The explosion sank the boat and killed four men. It also set light HM Trawler Honjo which was destroyed along with two of her crew by the fire. A third boat, HM Trawler Imperialist, was also damaged, but suffered no fatal casualties.

There were teams of Italian frogmen and Spanish saboteurs operating in and around Gibraltar, but they do not seem to be directly connected. The Italians worked at first from a villa only three miles from Gibraltar, they later moved their operations to a tanker that was interned on the opposite side of the bay.

The Spanish were specially trained by Admiral Canaris' Abwehr and were only moderately successful, mostly causing damage to various shore installations. The destruction of Erin and Honjo seems to be the only success against an enemy vessel obtained by these teams. They continued to operate until at least early 1944, but several of these men were caught and executed by the British.