The British HMS Duke of York stopped the Gil Eanes on 1 November 1942 and a commando arrested Freitas.
The British had picked up radio traffic indicating naval espionage, possibly compromising secrecy on "Operation Torch".
On 15 October MI5 asked for permission to arrest the neutral Portuguese fishermen, since they knew of two radio contacts between the fishing fleet and the Germans.
Freitas was interned in "Camp 020" in London with 500 other spies, some of whom then radioed false messages to the Germans as double agents.
The Gil Eanes had been sailing close to General Patton's armada, en route to the invasion in Morocco ("Torch").