'Each year at Sheffield people come here prepared to bury documentaries and at the end of each year I think documentaries are in healthier shape than ever,' says Hamish Mykura, head of documentaries at Channel 4 and head of digital channel More4. 'Docs did definitely take a bit of a dip for a few years but I think they're really back with a bang.'

Mykura has been commissioning documentaries at the UK terrestrial channel for seven years. One of the slots he is responsible for is Cutting Edge, Channel 4's flagship documentary series which features documentaries from UK directors. In the past, six documentaries were commissioned per year; now this figure is up to 30 a year.

He is also responsible for commissioning work from international directors for True Stories, a documentary series on More4. It runs every week for 40 weeks and Mykura claims there are almost twice as many True Stories as there are Storyville documentaries on the BBC.

Although there is pressure on programme budgets, Mykura says it does not always affect factual programmes. 'Often US acquisitions, which are really expensive and take up a large chunk of the schedule, get squeezed first. If you cut those back there is a lot more space in the schedule that needs filling. It's quite a logical step to turn to factual documentaries which are not as expensive.' Currently Channel 4 is spending $203,000-$234,000 (£130,000-£150,000) for a 60-minute documentary.

Diana: The Witness In The Tunnel and 9/11: The Falling Man are two of the high-rating documentaries Mykura has commissioned for Channel 4. The channel also had impressive ratings for Touching The Void, which first aired in 2004 and took $14m at the worldwide theatrical box office a year earlier.

Despite these successes, Mykura says a theatrical release is always going to be the exception rather than the rule. 'If you're making a film for theatrical release you have to anticipate that people are going to want to come and watch it.

It's much harder with films that are really edgy or deal with a very difficult subject matter to expect people to pay $12 (£8) to go and watch them with their date in the cinema.'

The documentaries that do well in cinemas, he says, are those with 'a kind of movie theatricality about them'. He adds: 'The fact that they happen to be made with the language of documentary is in a way not the point.'

For 2009 and 2010 Mykura is looking at documentary films with a more theatrical take on factual subject matter. 'I'm quite keen to try and stir things up.'

He cites the work of controversial anatomist Gunther von Hagens as a strong possibility for one of the channel's future projects. 'That's classic factual subject matter about anatomy but it's done in an entirely different way. It's turned into a still show and done with bodies which for some people might be quite creepy but for others it's incredible.'

Mykura is optimistic about new opportunities for film-makers, given that the concept of documentary is constantly evolving and new technology is allowing people to make high-quality films more cheaply than in the past. 'I'm not a documentary purist but I think documentary in all its forms is in the best shape at the moment.'