Media: I guess that's why they call it the Blues

Police corruption, child abuse, war orphans - no subject is too gritty for documentary film-maker David Hart.

When David Hart's production company, Hart Ryan, began work on a documentary about the Merseyside police five years ago, John Major was still Prime Minister, the party he led still had a working majority in the Commons and the team he supported - Chelsea - had about as much chance of winning the league as Iceland had of reaching the beach volleyball finals at the Atlanta Olympics.

Since then, the world has spun more than 1,800 times. Chelsea lead the Premiership, Labour is in power, and although Iceland remain a marginal force in beach volleyball, Hart Ryan has finally finished the film about the police. The results will be seen tomorrow night when BBC 2 screens the first in the five-part series, Mersey Blues.

OK, so there were certain extenuating circumstances, like the arrest and prosecution for corruption of one of the featured detectives. That delayed the film by a couple of years, but that still makes a total of three in the making. Such a protracted approach to the productive process is rare to the point of anachronistic in quick-fix, while-you-wait Britain. It is not necessarily an operating standard at Hart Ryan, but nor is it feared or frowned upon by Hart. "We make programmes that we stick by when others would have long given up," he says.

Orphans of War, a feature-length documentary screened on Channel 4 last year, took a year and a half to make, while the company has spent as much time on a Cutting Edge film scheduled for broadcast this year, which is still unfinished. Called The Accused, it follows a couple accused of child abuse who are effectively gagged from protesting their innocence by the legal requirement to protect the child's identity.

Still, the patience seems to be paying off. Hart Ryan has been shortlisted as best independent production company in this week's Broadcast Production Awards, while Orphans of War is nominated for best single documentary (a prize it is widely expected to take). Its debut docu-soap, the eight- part prime-time Lakesiders, was well received last year and has helped company turnover nudge pounds 2m. Around 35 people are currently working on two series for Channel 4 and two Cutting Edge films, while a commissioning editor at the network has just told them that Hart Ryan is their biggest supplier of documentaries.

It did not look this bright in April 1992 when, on his 50th birthday, Granada made Hart redundant after 20 years with the company. With the half century up, he admits feeling briefly that this was it, the end of his film-making career, and that maybe he just should take the pension.

"But I was pretty confident in the quality of my learning curve," he says. "I had been to film school, covered the Six Day War, I had been in Biafra and stood at Martin Luther King's lying in state."

And then there was the urging and support of his former Granada colleagues: Michael Ryan, who suggested they work together and, most significantly, Claudia Milne, who by then was at 20/20. During a yachting holiday that summer, she persuaded the pair to make a Cutting Edge film about maltreatment at Broadmoor.

The Cutting Edge team at Channel 4 suggested they make some more. The result was Navy Blues, a two-parter about the Navy's Special Investigation Branch that drew in seven million viewers, then the highest audience for a Channel 4 documentary. More significantly, it drew public attention to the persecution of homosexuals in the services and helped ensure the issue reached the floor of the Commons.

Hart Ryan followed up with Shops and Robbers, a landmark film that pulled in 10 million and beat ITV and BBC in the ratings. The back room in Hart's Tooting home was no longer large enough to house the company's rapidly expanding workload and ambition. There was the intensely controversial two-part film Traitor King, which exposed Edward VIII's far-right sympathies, and The Care Connection from the Dispatches strand, which revealed that children in care were being recruited as prostitutes.

"Leaving Granada was the best thing that ever happened to me, although I didn't think it at the time," Hart says. "It re-energised me. At 50, if I'd have stayed, I'd have been making the odd film and looking forward to retirement. Whereas now..." But he is saddened by what his and other colleagues' departure has come to signify. "The old Granada of Sidney Bernstein and David Plowright was a place you felt safe. If you had a story and you believed in it, they would back you.

"We were savaged over the tea programmes [which revealed the dreadful conditions in which Sri Lankan tea pickers worked] because we attacked Brooke Bond and the Co-op. We were summoned to Sidney Bernstein's office and I thought we were going to get a bollocking. In fact, they said `let's get the bastards'. I've worked for TV companies where, at the first sign of trouble, everybody starts running. You don't get any support and you think twice about what you know to be the truth.

"Current affairs and factual output has changed for a number of reasons, a lot of it to do with money. In the Seventies, they put resources into something knowing that after six months nothing might happen and we'd have to junk it. The whole question of risk has been taken out of television. Risk-taking is financially unacceptable, so the quality of television has declined as a result.

"The movement within TV, not just Granada and ITV, is towards a position where the first thing anyone is interested in is what sort of audience is it going to get. British television is a lot worse off for that."

Alan Hayling, the editor of documentaries at Channel 4, says: "David's strength is film-making which has a real documentary function. He makes social documentaries that are different, but he has a popular touch. That is a tremendous skill. Traitor King was attacked by historians but no one has been able to fault its research. It made a really important contribution to the understanding to what Edward did at the beginning of the war."

Hayling believes Hart's other great strength is his willingness to support young programme-makers, "to give them a break and some kind of training". Sam Kingsley was a press officer at Channel 4 with no film-making experience before she helped produce and direct Orphans of War. The film follows the photojournalist Nick Danziger as he attempts to raise three Afghan children adopted from a Kabul orphanage. It is a moving story open to all sorts of sentimentality, but the understated film keeps pathos in check and lets the characters lead the narrative. "It's a tremendous film," says Hayling, "which raises all sorts of interesting questions about refugees, the war in Afghanistan, adoption and how Nick is dealing with it."

Jenny Crowther was once a secretary at Channel 4. Four years ago, she produced The Care Connection for Hart Ryan, and now she has directed Mersey Blues. It is an observational series with extraordinary access to the Merseyside Police, owing less to the new vogue for docu-soap than to the traditional, issue-led documentary-making that Hart practised at Granada - the issue in this case being the unequal struggle between Liverpool's drug barons and its chronically underfunded police force.

It follows officers on drugs and firearms raids, portrays success as well as failure, and tracks a murder investigation. The recurring theme is austerity, from the bleak backdrop of the city to detectives willing to work overtime for nothing (or "for the queen", as it's known). It features CCTV footage of doormen being shot at a Liverpool night club and, something of a break for the programme team, the arrest for corruption of one of the detectives in the series, Elmore Davies. Last year he was found guilty and sentenced to five years in prison.

"I don't think that [his arrest and conviction] was luck, because I think it's very sad," says Hart. "He was very helpful to us. I never believed for one moment he was capable of the acts he was convicted for. I was astounded when it happened and, if given the choice between a scoop and him not being guilty, then it's the latter, because it's a life that's been ruined."