THEY haven’t even finished filming series three but the BBC has already signed up the stars of award-winning thriller Killing Eve for a fourth, Metro can reveal today.

Executives were fearful that Jodie Comer, 26, who plays psychopathic assassin Villanelle, and 48-year-old Sandra Oh (MI5 agent Eve), who is also executive producer, could be snapped up by Hollywood. So bosses dropped their usual policy of commissioning shows only after the last one is aired — series three will be shown next year — and agreed on a series four.

Comer, who is currently in talks to star in Ridley Scott’s The Last Duel with Ben Affleck, was recently seen filming series three in London disguised as a motorbike cop.

A Los Angeles source said: ‘There is a concern — and rightly so — that Jodie and Sandra’s standing now in Hollywood is so high that the offers to do other projects will simply be too great to resist, and that could mean them waving goodbye to Killing Eve.

‘So the cast have been verbally assured that the fourth series is moving ahead and to keep time free in 2020. The BBC would hate to see Jodie leave because of a big movie offer.’