The Crown star, 31, and Emma actor, 30, allegedly called it quits last year because their relationship had ‘suffered’ as a result of their careers ‘taking off’.
The couple ‘gradually grew apart’, apparently, while spending long periods of time away from each other, working on different films.
The source added: ‘Last year they made the difficult decision to go their separate ways and they both think its for the best. It’s all very amicable – things just weren’t working out.’
Vanessa spent months filming Mission: Impossible – Fallout in 2018 and last year for Fast & Furious Presents: Hobbs & Shaw.
Meanwhile, Callum’s currently in the latest film adaptation of Jane Austen’s Emma (can’t wait for it) and recently starred in the BBC1 conspiracy thriller The Capture as well as 2018’s Fantastic Beasts: The Crimes Of Grindelwald.