Comedian Dave Allen has died at the age of 68, his agent said.

The Irishman died in his sleep at his west London home.

Allen was a TV favourite with his shows Tonight With Dave Allen and Dave Allen At Large. He leaves a wife, Karin, and three children.

Allen's agent, Vivienne Clore, said the cause of death was unknown. The comic had not been suffering from any major illness.

Allen famously delivered his comedy routines sitting on a stool with a cigarette and drink in hand.

He was considered one of the first alternative comedians, telling risque jokes about sex and religion and making frequent use of the f-word.

Born David Tynan O'Mahoney in 1936, he grew up in Dublin and moved to Britain aged 21.

He became a Butlins Redcoat before making his TV debut on New Faces in 1959.

Several years on the stand-up circuit followed, including tours with the Beatles.

After appearing in his own show in Australia, he landed his first British TV series, Tonight With Dave Allen, in 1967 followed by The Dave Allen Show in 1968.