Why the documentary must not be allowed to die

What concerned the regulator and the ambassador was the power of a single documentary film: the power of its facts and witnesses: especially young soldiers speaking the truth and treated sympathetically by the film-maker.

I was a newspaper journalist. I had never made a film before and I was indebted to Charles Denton, a renegade producer from the BBC, who taught me that facts and evidence told straight to the camera and to the audience could indeed be subversive.

This subversion of official lies is the power of documentary. I have now made 60 films and I believe there is nothing like this power in any other medium.

In the 1960s, a brilliant young film-maker, Peter Watkins, made The War Game for the BBC. Watkins reconstructed the aftermath of a nuclear attack on London.

The War Gamewas banned. "The effect of this film," said the BBC, "has been judged to be too horrifying for the medium of broadcasting."

The then chairman of the BBC's Board of Governors was Lord Normanbrook, who had been Secretary to the Cabinet. He wrote to his successor in the Cabinet, Sir Burke Trend: "The War Game is not designed as propaganda: it is intended as a purely factual statement and is based on careful research into official material … but the subject is alarming, and the showing of the film on television might have a significant effect on public attitudes towards the policy of the nuclear deterrent."

In other words, the power of this documentary was such that it might alert people to the true horrors of nuclear war and cause them to question the very existence of nuclear weapons.

The Cabinet papers show that the BBC secretly colluded with the government to ban Watkins' film. The cover story was that the BBC had a responsibility to protect "the elderly living alone and people of limited mental intelligence".

Most of the press swallowed this. The ban on The War Game ended the career of Peter Watkins in British television at the age of 30. This remarkable film-maker left the BBC and Britain, and angrily launched a worldwide campaign against censorship.

Telling the truth, and dissenting from the official truth, can be hazardous for a documentary film-maker.

In 1988, Thames Television broadcast Death on the Rock, a documentary about the war in Northern Ireland. It was a risky and courageous venture. Censorship of the reporting of the so-called Irish Troubles was rife, and many of us in documentaries were actively discouraged from making films north of the border. If we tried, we were drawn into a quagmire of compliance.

The journalist Liz Curtis calculated that the BBC had banned, doctored or delayed some 50 major TV programmes on Ireland. There were, of course, honourable exceptions, such as John Ware