Julia Roberts' younger, half-sister Nancy Motes has died of an apparent drug overdose.
Lieutenant Larry Dietz, of the Los Angeles County coroner's office, says Motes, 37, was found dead in a Los Angeles home on Sunday while dog-sitting for a friend.
Dietz says an autopsy has not been performed and there are no preliminary findings about how Motes died.
Motes spoke last year of her struggle in growing up as the "fat little sister" of the actor who starred in Pretty Woman.
"When you're in a family of very, very exceptionally beautiful people, it's intimidating," she said.
Motes, who dropped half her body weight after having gastric bypass surgery in 2010, also claimed that her star sister used to tease her over her weight.
“When I was in high school and she was an adult, she would just let me know that I was definitely overweight,” Motes told New York Daily News in August.
“She would make it quite clear to me and in a not-so-nice manner.
“It just makes me feel incredibly hurt and very sad."
In spite of this, she said Roberts was a “good big sister who played with me a lot”.
But the relationship between the two was strained.
Motes, who worked as a production assistant on the TV show Glee - a job Roberts helped her secure - said depression led to her weight ballooning to nearly 140 kilograms.
She expressed hope that by losing weight and attempting to turn her life around she would start to repair her damaged relationship with Roberts.
“I think we're both trying to change our opinions of each other,” Motes said.
“It's a work in progress. It's not going to be fixed overnight, nor do I think it's going to be fixed at this point by me just getting skinny.”
Motes was set to marry her partner in May this year and, despite reports that Roberts was not planning to attend, she said: “My family, we love each other absolutely. I love Julia absolutely, and I have no doubt she loves me.”
Roberts, 46, has yet to make a comment on the death, but her family released the following statement: "It is with deep sadness that the family of Nancy Motes ... confirms that she was found dead in Los Angeles yesterday of an apparent drug overdose. The family is both shocked and devastated."
Roberts and her husband Daniel Moder are parents to twins Hazel and Phinnaeus and son Henry.
-Fairfax Media and AP