CODE breaking researchers have deciphered the cryptic military messages of a prisoner of war who spent his later years living in a Suffolk village.

East Anglian Daily Times: One of John Pryor's letters sent home from a German PoW campOne of John Pryor's letters sent home from a German PoW camp (Image: Archant)

Commander John Pryor’s wartime tale could have been copied from the pages of a spy novel – but he kept it secret until his son discovered the cipher hidden in his letters home.

Spending his last 30 years living in Snape, near Aldeburgh, Cdr Pryor never fully revealed the truth about his letters, which were always addressed to his grandfather but passed censors on both sides of the conflict.

When his son Stephen, a Plymouth University governor, enlisted the help of academics using code-cracking techniques, it was mathematics professor David McMullan who managed to interpret their contents using the knowledge of MI9 codes and a great deal of perseverance.

The MI9 code was used by the secret service to help escape and evasion. It was prisoners of war like Cdr Pryor who made it possible by sourcing equipment and supplies for breaking out. But his letters also passed on information about key German sites like munitions dumps.

The decoding project was set up by a university pro-chancellor working on a PhD about silk escape maps created by MI9. During a conversation with Mr Pryor, she discovered his father had written a number of coded letters from German PoW camps following his capture while trying to evacuate soldiers from Dunkirk.

Every fourth and fifth word in the letters was coded - but if those words happened to be “but” or “the”, it then triggered an intricate alphabetical sequence used to hide requests for items such as maps and passports.

Mr Pryor said: “I had known for 30 years that my father had these letters, but he could not remember the full code and so their contents lay hidden.

“His letters from the camps were always addressed to my grandfather but would have already passed through German and British censors, the latter picking up any coded requests.

My father was among the tens of thousands of young men who as PoWs lost the best years of their youth and could never hope to regain them. But I can now see that despite their plight, he and his peers took incredible risks and it has only made me admire their resilience and ingenuity even more.”

Cdr Pryor sent 20 letters home from the Marlag und Milag Nord death camp in north west Germany - the setting for 1953 British war film Albert RN.

He continued to serve in the Navy until his retirement, when he moved to Snape and became involved with producing the Aldeburgh Yacht Club’s annual sketch plans and sailing directions and carried out surveys of the Ore entrance. He died in April 2011 aged 91.

His widow, Mary, who still lives in Snape, said: “He was chair of the parish council for five years and did a lot for the church. He was very involved.

“He did talk about the letters but would say he didn’t remember much. Whether that was by design, I don’t know.

“The camps were full of a lot of young men who didn’t want to be there. They got hard punishment if they were caught trying to upset things.”

Plymouth University is now keen to hear from families with similar letters. If you want to uncover a loved ones’ hidden wartime history, email alan.williams@plymouth.ac.uk.