[4] While interned, Lingshaw decided to collaborate with the Nazis and, on 16 August 1943, he was released to travel to Berlin where he was employed to teach English to a group of 15 women working in the German propaganda service.
[5] He worked on minor duties for the New British Broadcasting Station unit of the Reichs-Rundfunk-Gesellschaft, German State Radio, monitoring and recording the BBC's wartime news bulletins.
In 1944, Lingshaw appears to have fallen out with the NBBS as on 11 November 1944 he was sent back to internment, this time to Oflag V-B at Biberach, Bavaria, where he remained until 23 April 1945 when the camp was liberated by the French Army.
Lingshaw was committed for trial on 6 February 1946 at a hearing at Bow Street Magistrates' Court in London, where he was charged with aiding the enemy by monitoring radio broadcasts.
At his following trial at the Old Bailey on 1 March 1946, he admitted to having assisted in the production and recording of British news bulletins for the German State Radio and was sentenced to five years' penal servitude.