FOR DECADES, the identity of Judy Lewis’ parents was one of the best-kept secrets in Hollywood.

Not until Lewis acknowledged her story in the 1994 autobiography “Uncommon Knowledge” did the general public know the truth: Lewis was not the adopted daughter of Hollywood starlet Loretta Young, but had been conceived out of wedlock by Young and Clark Gable while the two filmed “Call of the Wild” in the 1930s.

Lewis died Friday in the Philadelphia suburb of Gladwyne, said Rodger McKinney, owner of the Chadwick & McKinney Funeral Home. Services will be held Saturday.

Lewis, of Palm Springs, California, was raised in Los Angeles by Young as her adopted daughter. She was an adult when she learned that Young, a devout Roman Catholic, conceived her during an affair with Gable in the 1930s.

“At the time, what Loretta Young did was completely successful,” said Leonard Maltin, a film critic and Hollywood historian. “The general public never had any inkling that she had done this. It protected her stardom and her image as a wholesome young woman.”

Lewis was born 6 November, 1935, in Venice, California, and went on to perform on Broadway and television in her own career.

She also produced the soap opera “Texas,” a spin-off of “Another World.” In the 1980s, she earned psychology degrees, advocating for children’s rights and counseling teenagers. She later became a psychotherapist in Los Angeles, something she pursued until her illness.

In 1994, she wrote “Uncommon Knowledge,” acknowledging her parentage publicly for the first time. Her mother was a single Catholic and Gable was married at the time of her birth, and the news would have led to scandal, so she created the story that Lewis was adopted.

“The situation in which they found themselves in 1935 would not have posed such a problem in the Hollywood of today,” Lewis wrote in the book.

Lewis wrote that Young kept her sequestered with a nurse for months after her birth, and that she was then turned over to an orphanage. When she was 2, Young brought her home as her adopted daughter.

Before her memoir was published, the identity of her parents had long been rumoured. Maltin said the truth was never truly public, however, until the memoir, in which Lewis describes her mother telling her the truth in 1966.

In the book, Lewis said Young told her then: “‘Well, he was your father. … He was darling. Sweet and very gentle. … He was married, so when I discovered I was pregnant with you, I was frantic and terrified. It would have ruined both our careers, a scandal like that.’”

Lewis’ survivors include her daughter, three half brothers and her partner, Steve Rowland. Another memorial service is being planned for later this month in Los Angeles, McKinney said.