An argument between a spy and his wife almost resulted in the exposure of the D-day operations to invade Nazi controlled Europe in World War II, according to secret MI5 files released today (28 September).

Double agent Juan Pujol orchestrated a sophisticated British disinformation campaign, helping to convince the Nazis that the Allied D-Day landings would take place in Pas-de-Calais, leading them to divert men, weapons and resources from the real site of the landings in Normandy.

Pujol's wife, Araceli, was confined to their London home during the operation in an effort to conceal the spy's identity. The documents

recently released papers reveal that she threatened to blow her husband's cover unless she was allowed to travel to Spain and visit her mother.

Codenamed Agent Garbo, Pujol ran a network of agents sending false information to the Nazis about the Allies' D-Day plans.

The family was based in Harrow, north-west London, however Mrs Pujol struggled to come to terms with the family's double life and homesickness. She reportedly missed Spanish food, and was upset by her husband's extended absences.

Out of concerns they might be recognised, the family were restricted from leaving their London home.

In an exchange with Pujol's case officer, Tomas Harris, she threatened to expose his identity to the Spanish embassy. "I don't want to live five minutes longer with my husband," she screamed in a recording of the conversation released by the National Archive. "Even if they kill me I am going to the Spanish embassy."

The British were reportedly so concerned that she would attempt to spill the secret to the facist Spanish authorities, that they stationed police outside the embassy.

Master of deception Garbo hatched a plan though that persuaded his wife to stay quiet. According to the papers, he rejected a suggestion from Harris that he tell his wife he had been sacked. Instead he persuaded her that her outburst had led to a violent quarrel between him and British authorities and he was arrested. She was even taken to visit him in a prison camp where he was handcuffed, unshaven and blindfolded.

She then met MI5's legal counsel, Maj Edward Cussen, who told her he had decided to release her husband to continue his mission, however "he reminded her that he had no time to waste with tiresome people and that if her name was ever mentioned to him again, he would simply direct that she should be locked up," Mr Harris noted. "She returned home very chastened to await husband's arrival."

Pujol is widely regarded as one of the most successful double agents in history, with the Nazis so convinced of his loyalty they awarded him the Iron Cross medal. After the defeat of Nazi Germany, he was awarded an MBE by Britain.