This follows a deal Just Television signed with Dispatches in September to become its in-house investigative team. Dispatches is made by a large number of production companies on contracts that rarely last more than three months; getting a long-term deal to uncover stories is a coup that has made the world of investigative television journalism quite green with envy.
But the company's position as Channel 4's favourite bloodhounds would seem to be deserved. Last month one of Trial and Error's key campaigns was vindicated when Danny McNamee had his appeal against conviction for the IRA Hyde Park bombing upheld. Since setting up in 1992, Just Television has managed to get 20 convictions quashed.
David Jessel denies that he and his partners, Stephen Phelps and Steve Haywood, are making a killing from miscarriages of justice: "The contracts from Channel 4 allow us to support on-going investigations and we have what you could call our pro bono arm. For example, there is the case now of Tony Dickinson, a alcoholic who was convicted of setting fire to a house in which two people died. Now, we haven't made a programme about him, but we have disagreed with the Criminal Cases Review Commission's decision to reject his case. So, we are taking it to judicial review, but we've not made a programme about him.
Jessel, Phelps and Haywood walked out of the BBC as a group to join Channel 4 when the BBC was refusing to make more than a few episodes of Rough Justice a year. The walk-out was not just because of lack of work: "You can't very well say to people, sorry you have to stew in jail another year to fit in with the BBC's scheduling plans," Jessel points out.
Jessel had joined Rough Justice in 1985 after a career mainly in BBC radio and on the precursor to Newsnight, 24 Hours. Once on Rough Justice he realised he had found his niche: "There is definitely a selfish sort of satisfaction attached to the job. Better journalists than us reveal huge famines or corruption, whereas we focus on just one tragedy, although it is a heightened tragedy because being imprisoned for something you haven't done is like being tortured for information you don't have."
Jessel believes that the research skills perfected on Trial and Error - "We have our homework marked by the Court of Appeal, so it has to be pretty good" - won them the Channel 4 contracts. Just Television has already branched out into other current affairs topics - including the Monica Lewinsky case and, this week, an examination of the evidence in the Lockerbie bombing.
Some in the industry see Just Television's Dispatches and Channel 4 News contracts as evidence that the production company is a kind of conscience for Channel 4. "When Dispatches was cut back to half an hour and Dorothy Byrne was brought in from The Big Story there were worries that the programme would go down-market," says a rival producer. "If 20/20, who do The Big Story for Carlton, had won that contract, it would have been a bad sign.
"Just Television is a very solid, respectable face for Channel 4. But the admiration for Jessel and his team is tinged with jealousy: "They have the best people because the Trial and Error contract allows them to keep them," says the rival. "Trial and Error has been used as a base to make the company strong."