Former servicemen and women account for more than one in ten maximum security prisoners in the nation’s jails.
More than 800 military veterans are currently held in category A jails, which house the country’s most dangerous inmates.
Among 16 prisoners on a single landing at HMP Frankland, seven are ex-Forces personnel.
The jail’s other inmates include Yorkshire Ripper Peter Sutcliffe and Soham fiend Ian Huntley.
The majority are serving time for sex offences or violent crimes including murder – and many are suffering from mental health problems such as post-traumatic stress, says an NHS report.
Precise figures for the total number of veterans in prisons in England and Wales do not exist.
But sources have told the Sunday People the number is rising every year. And that is being linked to the growing problem of undiagnosed PTSD among veterans.
The Sunday People’s Save Our Soldiers campaign is calling for better care for veterans and serving forces members, and for greater resources to tackle post-traumatic stress.
The charity Care After Combat says 75 per cent of veterans in prison have some form of mental health problem.
Head of research Dr Nicholas Murdoch said: “Veterans are the biggest occupational group in prisons. The number is increasing every year. The convictions are quite broad.
“Violence is common. We are seeing more individuals who served in recent conflicts.”
Double killer Jimmy Johnson, decorated for his service in Northern Ireland, is now serving life. He is co-founder of the group Veterans in Prison and is the author of the Veterans’ Survival Guide.
Now in his 70s, Jimmy has been diagnosed with PTSD but says he had never heard of it until he was jailed for his second murder.
He said: “Sadly there are a number of veterans serving time with me, six on the same landing.
“Five of them are squaddies who served in conflicts, and five are serving life for murder.
“Despite combat-related PTSD having received a lot of publicity in recent years, the problem of the high number in prison carries on.
