Oscar winner Patty Duke died this week at the age of 69. With renewed interest in her career as well as her personal life, interest resurfaced in the unusual story about how her son, Sean Astin, learned the true identity of his biological father.

For years, John Astin, star of the Addams Family, was believed to be Sean's parent, and John raised Sean as such. But his mother wasn't entirely sure; when Sean was born in 1971, Duke was the subject of tabloid fodder as she'd ended a relationship with 17-year-old Desi Arnaz Jr., and then spontaneously married Michael Tell - a man who was subletting her apartment - before divorcing him 13 days later. She assumed that the father of her child was Astin — himself married when they began an affair.

People notes how Austin came to be unsure about his conception, and had a DNA test done around 2001. That revealed Tell to be his biological dad. For his part, Sean continued to view John as his father, while maintaining a relationship with all three. Admirably, he was a good sport about the ordeal.

Oscar winner Patty Duke dies at 69.

"I have a good relationship with Mike," he told People. I don't fault anybody, I don't fault myself or with Desi, who is like my godfather, I have such a powerful love bond with this man, he's a gorgeous human being."

WATCH: Sean Astin says mother Patty Duke was 'suffering terribly'