Dyke orders the BBC to make its ultimate documentary

Secret history: Director general seeks to preserve Corporation's story in words of those who were there

Greg Dyke, the director general of the BBC, has been seeking inspiration for the future in the corporation's past. As he considers how to reform the Beeb for the digital age, he has watched hours of old interviews with Hugh Greene, a Fifties predecessor, to learn how he shook up the stuffy BBC of the post-war era.

The interviews form part of a unique in-house archive chronicling the story of broadcasting in Britain in the words of those who were there, but which has operated on the BBC's margins. Now Mr Dyke has decreed this "oral history" must be expanded and properly preserved, alongside the technical artefacts that help to tell the corporation's story.

For years, it was often enthusiastic technical staff who saved important pieces of BBC heritage. Engineers would take home interesting items of old equipment rather than see them end up on the tip. Now this ad hoc system has been formalised in a special department, under a dedicated head of BBC heritage, Robin Reynolds.

An appeal to old staff has already brought in equipment of historical value. And Rory O'Connell, a curator who started work at the BBC from the Museum of London just before Christmas, aims to track down other pieces languishing in corners of Broadcasting House and Television Centre. They may be brought together in a dedicated museum, or they go on show in the BBC's offices as a reminder of the past.

The BBC is determined to preserve its history through the spoken word. A long-standing programme of recording interviews with senior executives will be widened to take contributions from other BBC employees and popular on-screen faces. Other staff members are expected to contribute to a full understanding of, for instance, the unpopularity of the reforms of John Birt, Greg Dyke's predecessor. Mr Reynolds admits the problem is largely a question of who to leave out. "You can't do everyone," he said. "It would have been great to do [the football commentator] Kenneth Wolstenholme before he died, on the [1966] World Cup."

Other interviews capture in detail broadcasting milestones such as the funeral of Princess Diana and the Millennium celebrations. All are given on the basis that they will remain confidential until the interviewee dies.

The aim is to extract full and frank disclosure about controversial events, such as the 1985 row over Real Lives, a programme about Northern Ireland which the then Conservative Government demanded should be banned, or more recent events such as the decision to establish new digital channels.

Mr Dyke and the BBC chairman, Gavyn Davies, have watched the interviews conducted with Hugh Greene, who tried to shake up the BBC to meet the challenge of its new rival, ITV. Mr Reynolds said Mr Dyke was interested because he too, wanted to change the culture of the BBC, notably in his "cut the crap" campaign.

Mr O'Connell said with major developments planned for Broadcasting House in London and in cities such as Glasgow and Birmingham, his team expects the next couple of years to be busy. "Museums usually get to pick over dead history. This is a mixture of the museum world I know, and working in a living industry. It's completely fascinating."