The spy who loved free – but was she really a Nazi agent?

One married UK officer asked Sophie Kukralova to be his wife and a second threatened to have her arrested as a spy unless she slept with him, according to newly declassified documents.

Kukralova was arrested and interned by the British in Palestine during the war, after arousing suspicion for her close interest in military matters, unexplained wealth and claims of top-level Nazi links.

A March 1944 report to MI5 notes there is no definite proof she is a German spy, but it says: "With her cosmopolitan and unscrupulous character, her interest in espionage, her unusual knowledge of armaments and military affairs, Sophie would, if released, be a potential menace to security wherever she was."

Her file also records that she "acquired a most undesirable familiarity with British military personal, including at least one NCO (non-commissioned officer) engaged on most secret work".

German documents uncovered by UK intelligence after the war suggested she was indeed a spy, codenamed R 37 49, who had planned to get herself adopted by UK citizens to acquire a British passport so she could travel to Bombay to arrange contacts for another Nazi agent. She was jailed five times by the Germans, before turning up in 1941 in Budapest, where she befriended a London-born engineer called Maxwell Clapham and his wife Josephine.

Kukralova persuaded the Claphams to adopt her in May 1941, although she did not get British nationality. Later that year, she and Josephine Clapham left Budapest and travelled to Cairo, where they aroused "considerable suspicion" before being arrested and interned in Palestine.

British intelligence officials admitted the evidence that Kukralova was a German agent was "somewhat inconclusive".

She was freed from internment in 1946, and MI5 made no objection when she applied to visit Britain in March 1951.