OXFORD Castle Unlocked will feature in a new BBC 1 documentary series exploring historical cases of capital punishment.

'Murder, Mystery and My Family' will view historic cases through the eyes of the descendants of those put to death.

The episode is due to be broadcast on Wednesday and will follow the story of Henry Seymour, who was convicted of murder and executed at the former HMP Oxford site in 1931.

The 45 minute programme will see his grandson Tony introduced to historians and experts who believe Seymour may have been wrongly convicted.

Segments of the documentary were filmed at locations across the historic site, including prison cells.

Paul Kyberd, who was a prison guard at HMP Oxford and now works at the Castle as a tour guide, lent his knowledge and experience to the documentary.

He said: "It’s a fascinating case. As a former member of The Oxford City Police and Thames Valley Police and 22 years as a detective, I feel that the evidence is inconclusive.

"I suspect that if the trial took place today the outcome would be very different!

It will be broadcast at 9.15am on Wednesday.