In October, producers announced that the "Underworld" actress had signed on to appear alongside Matthew McConaughey and "Crazy Rich Asians" breakout star Henry Golding in the upcoming action-crime film, with the project to follow a British drug lord who tries to sell off his highly profitable empire to a dynasty of Oklahoma billionaires.
However, an insider has now alleged to The Sun that Beckinsale pulled out of the film on Monday, November 26, after she decided that she could "no longer" devote herself to the movie.
"Kate turned up this week and decided she didn't want to play the role anymore," the source commented. "She explained that other stuff in her life, including an ill family member, meant she could not commit."
Representatives for Beckinsale, Dockery and Ritchie have not yet commented on the report.
Ritchie penned the script for "Toff Guys" alongside Ivan Atkinson and Marn Davies, while the film will be produced by Max Keene and Alan J. Wands.
Other cast members are set to include Hugh Grant and Jeremy Strong, with it anticipated that the feature will be in the same vein as the gangster flicks that launched Ritchie's career, such as "Lock, Stock and Two Smoking Barrels" and "Snatch".
Beckinsale was most recently seen onscreen in Adewale Akinnuoye-Agbaje's drama "Farming" and Marc Webb's "The Only Living Boy in New York". The 45-year-old recently landed a part in Charlie Day's forthcoming comedy "El Tonto" and is also in the pre-production stages of TV series "The Widow".
Meanwhile, Dockery is currently filming the hotly anticipated "Downton Abbey" movie.
A potential release date for "Toff Guys" has not been announced.