To celebrate the forthcoming 25 year anniversary of the extremely popular (and, it must be said, extremely funny) sitcom Porridge, BBC have decided upon a mockumentary about the life of Norman Stanley Fletcher since he left prison.

Ronnie Barker has filmed a small scene, and other surviving cast members have also recorded segments. The program will be going out over Christmas.

The idea isn't a first, after all, mock-dockumentaries have been around for some time now. However, going back to an old program as if it were factual is a novel twist on it.