An alleged jailhouse phone call between Khloe Kardashian and O.J. Simpson is once again raising questions about who the reality star’s father really is.

According to the Daily Mail, a guard at the Nevada prison where Simpson is serving a 33-year sentence for armed robbery claims he calls Kardashian weekly. “One day I could hear Khloe screaming in the phone,” says the guard, Jeffrey Felix, in a new documentary “Kardashian: The Man Who Saved OJ Simpson.”

“He said she was upset because she wanted him to take a paternity test, because the media is all over him, to see if O.J. is her actual dad — and O.J. told her ‘no.’”

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Simpson even allegedly asked for his advice. “I said, ‘Why won't you take it?’” Felix claims. “He said, ‘It's a family matter, it's none of the public's business.’”

Khloe herself as wondered — openly, on a 2009 episode of “Keeping Up with the Kardashians” — about whether Robert Kardashian is her real father. His second and third ex-wives both claimed he said she wasn’t his child, and while her mother Kris Jenner has admitted to being unfaithful to Kardashian during their marriage, she’s denied any claim he’s not Khloe’s father.