David Spenser, who has died aged 79, was the pre-eminent child radio star of the 1940s and 50s and will be best remembered for his portrayal on air of Just William. The author Richmal Crompton cast him in the role, in a series of dramatisations of her novels about the raucous but endearing 11-year-old outlaw.
This was in 1948, when David turned 14 and was already a seasoned radio actor – performing more than one play a week, he once told me. He had come into acting through a ruse set up by his ambitious mother and a BBC friend: he was lured into Broadcasting House and found himself in a studio being auditioned by the Children's Hour producer Josephine Plummer. For playing the lead in Just William he received the standard juvenile fee of four guineas – one-liner or starring role made no difference to the sum.
David's mother was to some extent the frightening "theatre mum" of cliche. Not only did she control him as a radio star, but she was also busy promoting his younger brother, Jeremy, to even greater heights of stardom in film and theatre. While David was playing William in 1948, Jeremy was enjoying his first film role, in Anna Karenina.
Before the second world war, the family had moved to England from Ceylon (now Sri Lanka), where he was born David De Saram. As with many boy actors, he managed to retain his treble voice beyond its natural term, and he became one of "Britten's boys" when he was asked to Aldeburgh to play Harry in the first production of the composer's Albert Herring. There, afraid of the dark, he was offered a place in Benjamin Britten's bed, as that was supposedly the only one at Crag House in Aldeburgh after a recent move from the Old Mill at Snape. Unlike his treatment of David Hemmings, Britten did not drop David after his voice had undeniably broken, and they remained good friends.
In the early 1950s, he managed a wobbly treble to play the part of Hurree Jamset Ram Singh in a TV serialisation of another children's favourite, Billy Bunter of Greyfriars School. Thereafter, as an adult actor, he joined the BBC Radio Drama Company and played as cast. He only once more resorted to a kind of treble voice, which matured during the course of the play, when he portrayed Kim in my lengthy dramatisation of Rudyard Kipling's novel. He was a perfect Kim in sound, and would have been so in vision had not Dean Stockwell got to the role before him.
As a grown-up actor, David developed a mellifluous voice of unusual quality, which was a pleasure to listen to but more suited to heroes than to those who sat below the salt. In Shakespeare, I think of his Troilus, his Laertes and, particularly, his Romeo to Judi Dench's Juliet.
To say that he was sensitive as a professional is an understatement. Even the most helpful advice could give offence and be taken as adverse criticism, with a huffy head-toss. "You mean you don't like my entire performance," he once said to me when I queried the reading of a certain line.
This sensitivity was put to better service when he left acting and became a full-time director-producer in the BBC radio drama department, of which I was then the head. As such, he was meticulous and fastidious, as well as liked and admired by technicians, actors and writers. So fine a director of radio plays was he that it was with great regret I saw him leave in 1987 to set up a TV production company, Saffron, with his life partner, the writer and producer Victor Pemberton. The company concentrated on TV arts documentaries and David directed programmes on Angus Wilson, Dodie Smith, Benny Hill and Gwen Ffrangcon-Davies. The last of these won an International Emmy award.
While David met with success behind the camera, his acting career in front of it had been busy and jobbing rather than distinguished. Only rather humdrum, often racially stereotyped, parts were offered to him and, unlike his younger brother, he was given no opportunity to shine when acting in films. The very titles of some of those in which he appeared indicate how his talent remained unstretched: The Stranglers of Bombay (1959); In Search of the Castaways (1962); The Earth Dies Screaming (1964); Carry On Up the Khyber (1968). In the 1972 film version of The Merchant of Venice, he played the turbanned Prince of Morocco to Maggie Smith's Portia.
On TV, he would end up with parts to help pay the rent rather than bring celebrity status. He had minor roles in nearly all the popular series of the period: Dixon of Dock Green, Z Cars, Softly Softly, The Saint, Adam Adamant Lives!, Pretenders. His appearance, and his talent, served him well in six episodes of Doctor Who – in the serial The Abominable Snowmen (1967) – when he played against Patrick Troughton's Doctor as Thonmi, a Tibetan monk.
He could, perhaps, have been the impoverished writer of plays for radio, had he been less painstaking and self-critical. He wrote a number of these – and very good they were of their type – and was responsible for one major, epic work, City of the Horizon, about the Egyptian pharaoh Akhenaten; his wife, Nefertiti; and his mother, Queen Tiye. This was broadcast in 1972 and again a few years later to much critical acclaim. He was also responsible for a mammoth dramatisation, John Galsworthy's The Forsyte Chronicles, in the early 90s on Radio 4.
He had a spiritual, dreamy nature and became much involved with the writings of the spiritual teacher George Gurdjieff. It was not the dressing up, showing off and display side of acting, writing and directing that really interested him, but the very essence of storytelling and performance that excited him and sent his imagination flying.
All this was a long journey from the 11-year-old boy bungling down the stairs at the opening of each 1948 episode, answering his mother's upward call "William!" with "It's all right, mother, I'm coming!''
He is survived by Victor and Jeremy.
• David Spenser (David De Saram), actor, writer and director, born 12 March 1934; died 20 July 2013
