Recognition of his talents only came relatively recently, when he was awarded best comedy actor at the 2005 British Comedy Awards for his roles as the beleaguered minister Hugh Abbot in Armando Iannucci’s Whitehall satire The Thick of It, and as the psychoanalyst treating various Paul Whitehouse characters in Help.

However, this triumph was overshadowed by his arrest in November 2005 during police investigation into child pornography on the internet. Charges of indecent assault on an under-16 girl were later added. He denies the charges.

Langham read English and drama at Bristol University before moving into comedy, his first TV appearance coming in Spike Milligan's Q in 1969. He also worked on Milligan In... three years later.

In the Seventies, he also worked as the only British writer on The Muppet Show, and made an unscheduled appearance on screen when Richard Pryor didn’t make it to the recording.

In 1979, he became a leading member of the Not The Nine O'Clock News team, but he was unceremoniously dropped after the first series, to be replaced by Griff Rhys-Jones.

He said the sacking left him distraught, and that he would ‘burst into tears’ if he saw co-stars Rowan Atkinson, Pamela Stephenson or Mel Smith in the newspapers up to two years later.

At the time, he also suffered drink and drug addictions, although he later overcame these problems admitting: ‘I stopped drinking and taking drugs because they were taking over my life.’

Langham went on to appear on Smith and Jones' own programme, Alas Smith and Jones, in 1989 as well as the BBC's and The Secret Policeman's Biggest Ball in the same year. His other TV credits include small roles Ben Elton’s sitcom Happy Families in 1985, and Chelmsford 123 in 1990 and Gimme Gimme Gimme in 199. And on film he has appeared in The Life of Brian, where he had a brief role as a centurion, Carry On Columbus and The Big Tease.

On stage, Langham played Arthur Dent in the first professional theatrical version of The Hitchhiker's Guide to the Galaxy, in 1979; and has appeared in Les Miserables (playing Thernardier in 1996), The Nerd and Pirates of Penzance.

He was largely absent from TV screens for much of the Nineties, until the 1998 BBC One sitcom Kiss Me Kate, which he wrote and starred in alongside Caroline Quentin and Amanda Holden.

His stock rose further with the acclaimed People Like Us, a spoof in which he played the hapless documentary-maker Roy Mallard, with typical understatement. The show began life on Radio 4 before transferring to BBC Two in 1999 – although he remained unseen on screen, appearing only as a voice from behind the camera.

Langham also directed the 2003 comedy cookery show Posh Nosh, starring Richard E Grant and Arabella Weir.

He has three sons by his first wife, actress Sue Jones-Davies, and two children by his second, stage director, Christine Cartwright.