Julia Roberts' mother has died

Actress Julia Roberts is reportedly in mourning following the death of her mother.

According to an unconfirmed report by In Touch magazine, Betty Lou Motes passed away aged 80 at a health centre in Santa Monica, California, on Thursday.

She had been battling lung cancer.

It comes a year after the death of Roberts' half sister, Nancy Motes.

Betty Lou Motes was devastated by the death of her daughter from a drug overdose at her home in Los Angeles in February last year.

Pretty Woman star Roberts had yet to comment on the report.