Coded letters sent from a British prisoner of war to his parents in Cornwall have been deciphered thanks to academics at Plymouth University.

Sub Lt John Pryor was captured at Dunkirk in 1940 and sent to a German prisoner of war (PoW) camp.

He was held for the next five years but as a reward for good behaviour he was allowed to send letters home to his parents in Saltash.

Those letters contained secret messages for the British military.

The research began after military intelligence expert Barbara Bond, a pro-chancellor at the university, heard about the letters from Sub Lt Pryor's son Stephen, a university governor....