Keira Knightley thought Pirates of the Caribbean would be 'a disaster'

Keira Knightley didn't have high hopes for one of the most successful film franchises of the 21st century, it has been revealed.

The revelation was let slip by Love Actually director Richard Curtis in a piece he's penned for the Radio Times, talking about reuniting that film's cast for a new Comic Relief special.

It's a passing comment made about Knightley that might have the 32-year-old actor cringing.

Curtis recalled filming the original Love Actually back in 2003, just before Knightley was due to start work on the first of the Pirates films.

"When we shot the film, I remember Keira Knightley saying that her next project was 'some pirate thing - probably a disaster'. That turned out to be Pirates of the Caribbean, in which Bill Nighy was also later a be-tentacled Davy Jones," writes Curtis.

You could forgive Knightley for her pessimistic view of the film's chances - after all, it was a movie based entirely on a Disney theme park ride. But Pirates of the Caribbean: The Curse of the Black Pearl garnered positive reviews from critics and became a roaring box office success, grossing more than US$654 million worldwide.

Knightley starred as Elizabeth Swann in a further two instalments in the franchise, which together grossed another $US 2 billion worldwide (although as the franchise wore on, some critics did indeed think it turned into a bit of a disaster).

Following a six-year hiatus for the series, Pirates of the Caribbean is set to return to the big screen this year: A fifth film, Dead Men Tell No Tales, will hit cinemas in May. Knightley is not involved in the project.