The astute businessman who gave us Kirsty and Cheggers

Known among his peers as "television's resident intellectual", David Elstein was an unusual choice for the Daily Mail's title of "new pornographer in chief". But the controversial Channel 5 boss, who stepped down yesterday, was responsible for presiding over a schedule which his director of programmes, Dawn Airey, once famously described as "films, football and f***ing".

Known among his peers as "television's resident intellectual", David Elstein was an unusual choice for the Daily Mail's title of "new pornographer in chief". But the controversial Channel 5 boss, who stepped down yesterday, was responsible for presiding over a schedule which his director of programmes, Dawn Airey, once famously described as "films, football and f***ing".

Although lambasted for its policy, Mr Elstein once proudly stated that every time the press published another article about "Channel Filth", "we fall about laughing ... the articles seem to have a positive effect on ratings".

In practice, however, Mr Elstein has been less of a purveyor of sleaze and more of an astute businessman - known in the television business as "two-brains". He joined the channel seven months before its launch in March 1997 and helped it beat all the targets.

Under his direction, the channel has honed its skills as television's resident provider of gruesome, titillating and voyeuristic material - as well as running a staple diet of straight-to-video movies deemed too unimpressive even for local video shops.

It is a formula that has proved surprisingly successful, reshaping the way television news is presented with Kirsty Young's famous stand-up delivery, and leading the way in the tactical scheduling of popular movies and the astute purchasing and reversioning of foreign programmes.

That said, rumours about his imminent departure have been rife in the industry for some time. They stemmed from news that the channel's majority shareholder, the £16bn company RTL, which owns a host of European television stations and Pearson Television in the UK, wanted to change its approach, steering it away from the "triple-f formula".

RTL would like Channel 5 to come up with a strategy for increasing its audience share to 10 per cent - and insiders there suggest that they wanted Ms Airey rather than Mr Elstein to take the project forward. It has also been suggested that Ms Airey, a television hot property, had been approached by other companies, including ITV.

Insiders believe it likely that she will turn Five into a general entertainment channel, a strategy that would appeal to RTL's boss, Richard Eyre, a devout Christian who does not much like the sleazier side of the programming.

Mr Elstein first made his presence felt in 1969 when he campaigned vigorously for the formation of Channel 4 - although he did not go on work for the new company. He is one of a generation of fiftysomething men, including John Birt, Michael Grade and Greg Dyke, who have shaped the direction of the key terrestrial channels.

Growing up in a solid Jewish middle-class home, he went to Haberdashers' Aske's school, where his contemporaries included Michael Green, chairman of Carlton TV, and Sir Nicholas Serota, director of the Tate Gallery. He became the BBC's youngest ever trainee, graduating to Thames Television, where he helped to set up Weekend World under the editorship of John Birt.

He joined BSkyB as head of programming in 1993, and two years later found himself moonlighting as chief executive of a BSkyB-led investment group that bid for the Channel 5 licence. Although it failed, Mr Elstein was approached by Lord Hollick, a Channel 5 director, for the Channel 5 post shortly afterwards.

He was recently a contender for the post of director-general at the BBC, being interviewed but losing to Greg Dyke, and for chief executive of ITV, a post which has been vacant for almost a year. But there is speculation that rather than take a job at an existing channel, he will start his own project.