A teenage girl from Hove was suspected of betraying resistance fighters in wartime France and becoming the mistress of a Gestapo officer.
The desperate story of survival and betrayal surfaced today with the release of historic MI5 Security Service intelligence files by the National Archives.
Antonia Lyon-Smith, the daughter of an Army officer, was 15 years old and on holiday when she became stranded in France after Nazi Germany invaded in 1940.
She was arrested by the Gestapo because of a letter she had written on behalf of the resistance movement led by Claude Spaak.
But, rather than being shot or sent to a concentration camp, she was kept as an office girl by the Gestapo in Paris.
While there, a German officer named Karl Gagel apparently fell in love with her.
Her file includes a letter from Gagel trying to make contact with Lyon-Smith after her return to Britain and reports of their interrogations.
She was questioned after the war but was reticent about her relationship with Gagel and her connection with Spaak’s organisation.
This led MI5 to suspect that she had become attached to Gagel and had betrayed the resistance.
Ed Hampshire, from the National Archives, said she was not pressed further because of her family links and young age.
She was not deemed a security risk as she was back home and due to marry.
She later wed, becoming Antonia Hunt, and published a memoir in which she said that she became engaged to four men during the war, without marrying any of them.
Gagel initially tried to claim that he did not have an intimate relationship with the teenager but said that “there was nevertheless an understanding that when Germany and Britain ceased to be enemies they would become engaged”.