Sarah Silverman shares chilling story of how her grandpa allegedly killed her brother

Sarah Silverman has revealed some dark family secrets, including the death of her brother at the hands of her grandfather.

The 54-year-old Saturday Night Live star said she had believed her three-month-old brother, who died before she was born, passed away in a tragic accident.

In a tell-all interview with Rolling Stone, Sarah said she had believed the story that her little brother Jeffrey had tragically fallen through a gap between the mattress and the bottom rail of the crib where he 'suffocated.'

The incident took place five years before she was born, as Sarah's mom Beth had won a cruise on a game show and had left the infant with the parents of her then-husband, Donald.

Sarah Silverman with her dad Donald in 2018 (Presley Ann/Getty Images for Hulu)

"But if you look back, there was never a lawsuit with the crib company or anything," she said.

Sarah - who is currently preparing to release a new special PostMortem, that reflects on the deaths of her parents - then said the story crumbled to smithereens when her late father Donald disclosed the truth.

Before his passing in 2023, she said her dad told her he believed Jeffrey had been killed at the hands of her 'violent' grandpa, Donald's own father, claiming he 'shook him in a rage'.

Explaining how the admission slipped out one night, the TV star told the news outlet that she finds comedy to be 'the relief valve', before admitting jokes can have a right time and place - as well as 'the worst and most inappropriate place'.

And it was a somewhat inappropriate place where Donald came to tell her the truth about Jeffrey.

The comedian says she believed her dad's theory (Tommaso Boddi/Variety via Getty Images)

She told the magazine her father came to see her production of Bedwetter in Manhattan, all five nights in a row, which features a scene about younger Sarah joking about Jeffrey's death.

Backstage, Donald then came forward.

"My dad says, ‘I always felt that he was crying or something, and my dad shook him',” she said. "As soon as he said it, it was like, 'Of course, that’s what happened'."

“My dad had a heartbreaking childhood,” Sarah also said. “His dad beat the s**t out of him every day, just mercilessly. He had a younger brother who wasn’t touched. His father made the kids call him Mr. Silverman.”

She described her father as her 'best friend' (Jason LaVeris/FilmMagic)

"His mother always stood by her husband. She watched him beat the s**t out of her son. I couldn’t ask my mom, because she was dead.”

Sarah, whose mom died in 2015, describes her late dad as her 'best friend' and 'buddy' who was 'always dropping bombs' like this.

The actress explains how her parents eventually went through an 'ugly divorce', with Donald remarrying shortly after the divorce was finalized.

PostMortem will be available to stream on Netflix from Tuesday, May 20.