For 13 years now, The Bill has been one of ITV's best-loved cop shows. As you wander around what used to be Her Majesty's Prison Oxford, where the 40-strong crew of the hit drama are four days into a five-day shoot, you reflect that people spent less time in here for murder than the show has been on the air.

The old prison is becoming a bit of a star itself. Slopping out and being banged up have been replaced by TV stars and big budget movies.

The trail to this jail is paved with misery and magic. Where once convicted felons arrived manacled and chained to begin sentences of various severity, today tourists, visitors and TV crews mingle.

Ben Greenacre is location manager on the Oxford shoot. And for once, his job is easy, despite the fact that the last two days of filming coincide with the latest couple of open days at the prison.

"That was the only potential problem," says Ben, "but everyone has been helpful and it's all been very easy - in fact, we're ahead of schedule."

For this episode, Oxford Prison has been transformed into HMP Newington. It's entitled Follow Through and should be on the small screen in around six weeks. For Ben, this will be the culmination of the work that began when he got a call from the director telling him what was required for this particular hour-long episode.

"Sometimes I have to find a chip shop or a four-bedroomed terraced house or whatever is needed. Then I do the deal with owners, think about the power supply and the parking and make sure the neighbours know what is going on. I've not worked on The Bill for long - last year I did the Spice World movie. We've got three units filming simultaneously, Red, Green and Blue, so some will be on location and some will be in the studio."

In the episode being filmed in Oxford actress Libby Davison and actor Ray Ashcroft team up to get to the bottom of a beaten-up women prisoner and some very dirty policemen.

As they film their final scenes before breaking for lunch, the sky starts clouding over and the old prison begins to look very grim indeed. Necklaces of barbed wire still clutch the high throat of the walls and in the shadow of the Debtors' Tower, Ben's walkie-talkie crackles as the voice of the assistant director requests quiet as they go for a take.

"Turning over", she says and silence fills the air. The open day visitors respect Ben's request to stand silently until they hear the magic word on the walkie-talkie: "Cut!" With the scene in the bag, Libby and Ray head off to the catering wagon and the lunch bus, a converted double-decker with tables. "I live in Newcastle, so being on location isn't much different for me from filming in London. It's been fantastic in Oxford - I've really enjoyed it here and it's been very positive," says Libby. She's been with the show for two and a half years and is grateful for the security it offers. She's married to Stephen, who she fondly describes as "The regular wage."

"The security of The Bill is very good," she admits. "It's the first time in 13 years in this business that I've a contract longer than nine weeks."

Ray Ashcroft has been with the show for three years now. He's a family man whose three children aren't impressed muc, by the fact that their father is on the telly.

"Blas is the word, I think," he says with a wry grin. But The Bill has no continuous storyline, which, for an actor with a family means that it's the only workable sort of job, because you're always getting time off. It's a load of fun and I don't take it - or myself - too seriously." In the converted Green Room, Libby stretches out on a sofa as Ray nibbles a healthy lunch. When Oxford Mail photographer Jon Lewis begins taking pictures of her in such an informal pose, Ray playfully bites the end off a tomato and sticks it on the end of his nose.

Lewis, however, is too much of a gentleman to ask him to keep it there for a picture.

And the crew and cast of The Bill seem too normal and down to earth, too matter of fact and practical to be anything that comes close to being precious or in danger of being labelled 'luvvie'.

They sound as if they've enjoyed Oxford and the old prison has once again proved a successful location.

The ghosts of executed prisoners may still howl softly around the condemned cell, but these days, you're reminded of Oscar's words: "Two men looked through prison bars - one saw mud, the other stars."

TV stars, that is.

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.