Judy Lewis: Actress eventually revealed as the love child of Clark Gable and Loretta Young

Though a successful actress and television producer, and later a qualified counsellor to young people, Judy Lewis will be best remembered as the love child of two of the biggest stars of Hollywood's golden age, Clark Gable and Loretta Young; Lewis was 31 years old before her mother eventually confessed the truth to her.

She had been conceived when the couple were on locationon the snowbound slopes of Mount Baker in Washington State, stranded by the worst blizzard the area hadsustained in 20 years while making a film version of Jack London's The Call of the Wild (1935).

Gable, who had just been nominated for an Oscar for his performance in It Happened One Night (1934), was becoming the screen's most popular male star. He was also a married man. Young, who had started her career as an extra in silent films at the age of four, was about to star in a religious-themed movie, The Crusades, and had recently signed a contract with 20th Century-Fox. Both stars were fiercely ambitious, and in the moral climate of the time, knowledge of their affair and illegitimate child would have ruined both careers. Young's devout Catholicism made an abortion out of the question.

Instead, after finishing her work in Cecil B DeMille's epic production, The Crusades (1935), filmed during her early stages of pregnancy, she went to Europe for a holiday, claiming exhaustion after a heavy filming schedule. (In London, her name was linked romantically with the tennis star Fred Perry.)

Returning to Los Angeles, Young stayed out of sight at a house in Venice, California, where she was tended by the family physician, who told her studio she was "seriously ill", needing rest and seclusion. She gave birth to her daughter, listed on her birth certificate as "Judith Young", in November 1935; 19 months later, Young "adopted" the child from an orphanage to which she donated a portion of her earnings for the rest of her life.

The child had the broad mouth of Gable and particularly prominent ears – Gable's ears had often been caricatured for their size. William Wellman, the director of Call of the Wild, when asked if the rumours were true, responded, "All I know is that Loretta and Clark were very friendly during the picture and it was very cold up there. When the filming was finished, she disappeared for a while and later showed up with a daughter with the biggest ears I ever saw except on an elephant."

In 1994 Judy Lewis wrote a book, Uncommon Knowledge, in which she described her early life and her mother's ambivalent attitude – after Lewis eventually confronted her mother about her parentage, her mother told her that she regarded her as her "mortal sin". That Lewis's father was Clark Gable was an open secret to most of the film community. In her book, Lewis describes her puzzlement at always wearing bonnets that covered her ears. "My mother emphasised the importance of keeping my ears covered whenever I would be seen by the public. I began to think of myself as deformed."

At the age of seven, after she told her mother that children at school were calling her Dumbo, she underwent an operation to flatten her ears. Her memoirs relate that she met her father only once, though at the time she knew him only as a famous star she had seen at the movies. She was 15 years old and returned from school to encounter him in the hallway. She describes how he sat beside her on the couch and asked her about her enthusiasms, her schoolwork and her boyfriend. Years later, she realised that her mother had arranged the meeting so that Gable could talk to his daughter.

In her memoir Lewis wrote that although she had a luxurious childhood in her mother's Beverly Hills home, she always felt an outsider, with no real identity. "It was always very difficult for me as a little girl not to be accepted or acknowledged by my mother, who, to this day, will not publicly acknowledge that I am her biological child." In 1940, when Young married the radio producer Tom Lewis, Judy took his surname, though he never adopted her.

After graduating from a Catholic girls' school, Lewis began her acting career in 1957 in New York, with a small role on Kraft Television Theatre. Other small parts followed, and then a major role in a new soap opera, Kitty Foyle, the first of many daytime serials in which she would appear. She also produced a short-lived daily drama titled Texas (1980), and spent a year on Broadway playing the role of Tiffany in Jean Kerr's hit comedy, Mary, Mary (1964).

In 1958 she met the television director Joe Tinney and they were planning to be married when Lewis told him she could not marry him as he knew nothing about her background. She recalled that he replied, "You're wrong. I know everything about you," and said: "It's common knowledge, Judy. Your father is Clark Gable."

It was another eight years before Lewis bluntly asked her mother if this was true. Young admitted the fact and explained the reasons for the deception. Later, when she heard that Lewis was going to write a book about her life, Young's anger led to an estrangement that lasted for three years. Young was determined that the story should only be told after her death, and when her authorised biography by Joan Wester Anderson was published shortly after her death in 2000, the full story was finally revealed.

Meanwhile, Lewis gave up her show-business career to study clinical psychology at Antioch University in Los Angeles, earning a bachelor's degree and a master's degree before working as a counsellor specialising in foster care, marriage therapy and counselling for unwed mothers.

Judith Young (Judith Lewis): actress and counsellor; born Venice, California 6 November 1935; married 1958 JoeTinney (divorced 1972, one daughter); died Gladwyne, Philadelphia 25 November 2011.