Best known for the words "Schh...you know who," William Franklyn's achievements stretched far beyond being the face of Schweppes.

The actor, who died of prostate cancer aged 81, lived in Putney, but spent his early years in Australia. He was the son of Leo Franklyn, the actor famed for No Sex Please, We're British.' But Mr Franklyn Sr had other ideas for his son, who he thought should be a journalist. However, when he saw young Bill performing in the comedy Arsenic and Old Lace' on the pier at Southend, after the young man returned from his stint as a Second World War paratrooper, he changed his mind, and suggested he had better stick with acting.

Mr Franklyn's acting career took in films, television series and panel games, as well as the famous tonic water advert which Schweppes eventually pulled after eight years because Mr Franklyn had become bigger than the brand itself.

He sported a face of steely determination as a spymaster in the 1960s television series Top Secret and gave an unemotional performance as a manipulated husband when he starred in the film Pit of Darkness in 1962.

At one stage he was always first choice for any kind of spy programme and was offered the role of host, quizmaster and interrogator in ITV series Master Spy.' He changed tack in 1977, playing an entertainments officer of an ocean liner in a television series called Paradise Island and then performed in a run of West End comedies.

But Mr Franklyn was not stumped for ideas when his acting career ran aground for a while.

He showed an entrepreneurial streak when he made ends meet by trundling a barrow around the wealthier parts of London and asking people for their unwanted goods, which he then sold as antiques.

He also took a turn on the other side of the camera when he directed There's a Girl in my Soup.

For this he had to quickly master Italian so as to be able to at least try to manage his Italian cast.

In 2004 to 2005 he was the voice of the Book in Radio 4's Hitchhiker's Guide to the Galaxy.' Mr Franklyn embodied the image of the stiff upper-lipped Englishman, whose hobbies fittingly included cricket, a sport to which he was totally devoted.

Perhaps equal to his passion for cricket was his love of retelling a good anecdote in his trademark silky smooth tones.

In 1952 married Margo Johns, by whom he had a daughter.

He is survived by his second wife, Susanna Jupp, and their two daughters.