A Watford school that featured in a fly-on-the-wall documentary nearly 50 years ago dipped into its past today (Tuesday) when the original director returned with a modern film crew.

Former pupils of what is now the Francis Combe Academy were also invited back as the BBC began filming for a new television series, fronted by veteran broadcaster Melvyn Bragg.

A large portable cinema drove through the academy gates to broadcast the award-winning film 'Our School', filmed in 1962 at the then Francis Combe.

At the time, a crew of eight, including director John Krish, spent six weeks filming classes and day-to-day school life to "lift the lid on the relationships between pupils and teachers".

Dozens of BBC archive films were released for the new documentary, which re-visits the original locations, and the Watford school was featured in the historic list.

Headteacher Leo Gilbert said: "It was completely out of the blue when the BBC contacted us. Having the ex-pupils back just helps you realise what an important part of the community the school was back then, and still is now, and it gives a great opportunity for the current students to see what they have achieved."

Few of the old buildings remain, and much of the previous school field has been built on, but with a £25million refurbishment planned to start in a few months' time, Mr Gilbert said it was an apt opportunity for the filming to take place.

"It gives us a chance to reflect on our past, and how the school has been for the past fifty years, before we take it to the next stage of its life," he said.

Current pupils joined ex-students in the cinema to view the 30-minute documentary and had an opportunity to discuss the school, past and present.

Head boy Harjit Hullait, 18, said: "It has been eye opening. It is things like teaching methods that really stand out, the metalwork class just doesn't exist anymore because of health and safety, which is a shame.

"I felt proud that the people in the film had been there before me and there was a sense of respect for the school that it has been here so long."

The film is one in a four-part series, A Day in the Life: Four Portraits of Post-War Britain, which was handed the award for Best Documentary at the 2010 Evening Standard Awards after its release by the British Film Institute last year.

Director John Krish last visited the school in 1962 but revealed a disagreement with the then headmaster meant the documentary was nearly never filmed.

Only when the National Union of Teachers, which commissioned Krish to film the piece, came back and demanded the film-maker be left alone, did the documentary go ahead.

Mr Krish, now 87, met some of the pupils he filmed on today's set.

He said: "I was pleased to see them and they all had fond memories of the filming. I wanted to be at the heart of the school in the documentary and I think I achieved that."

To see some of the former pupils who featured in the documentary, and find out what happened to them next, see Friday's Watford Observer.

The school will be featured in The Reel History of Britain when the programme is broadcast later this summer.