Cliff Robertson Cliff Robertson

Cliff Robertson, who won an Oscar for playing mentally disabled man in the 1968 film Charly and later played Ben Parker in the Spider-Man films, has died. He was 88.

Robertson died of natural causes on Saturday in Long Island, one day after his 88th birthday, Evelyn Christel, Robertson's secretary for 53 years, told The Associated Press.

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Besides his Oscar-winning role in Charly

— which was adapted from Daniel Keyes' short novel, Flowers for Algernon, and told the story of a mentally disabled man who becomes a genius after medical treatment — Robertson is also remembered for playing President John F. Kennedy in 1963's PT-109. The film, the first to portray a sitting president, depicts Kennedy in command of a torpedo boat as an officer in the Navy during World War II.Robertson, who also appeared in such films as Autumn Leaves, Gidget and Three Days of the Condor, made headlines in 1966 with his second marriage to one of the world's richest women, Dina Merrill, the heiress to the Post cereal fortune. They had a daughter, Heather Robertson, before divorcing in 1986.He made headlines again as the whistleblower on a Hollywood financial scandal in the 1970s. Robertson reported David Begelman, president of Columbia Pictures, to the authorities after he discovered that Begelman had forged Robertson's signature on a $10,000 salary check. Robertson said studios refused to hire him for four years after the scandal.

Check out all of Robertson's credits

Robertson also appeared regularly on the small screen. He starred in Rod Brown and the Rocket Rangers and won an Emmy for his work on a 1965 episode of Bob Hope Presents the Chrysler Theatre. He also appeared on The Twilight Zone, played the villainous gunfighter Shame on Batman, and had recurring roles on Falcon Crest and the short-lived NBC series The Lyon's Den starring Rob Lowe.His final film appearance was in 2007's Spider-Man 3 as Ben Parker, the deceased uncle of Tobey Maguire's Peter Parker whose death inspired the teen's transition into a superhero.Robertson is survived by a daughter from his first marriage, Stephanie Robertson Saunders, and a granddaughter. His other daughter died of cancer in 2007.