Myles played former private contractor Beth Bailey in last year’s Series 9, but the character will not appear in the new series, having been “decommissioned”.

The actress also played Madame de Pompadour in Steven Moffat’s 2006 Doctor Who episode, ‘The Girl in the Fireplace’.

In an exclusive interview with CultBox, writers Sam Vincent and Jonathan Brackley revealed: “Beth was… a type we hadn’t really seen on the Grid before. There were plans to explore that a lot more, show her torn between her new sense of public service and the pull of her lucrative past.”

They added: “So it’s a shame it didn’t work out – but on the other hand, it gave us an opportunity to create Erin and Calum.”

Erin Watts, Section D’s new leader, will be played by Lara Pulver (True Blood, Robin Hood) and Calum Reed, a new IT supremo, will be played by Geoffrey Streatfeild (Ashes To Ashes).

> Read our full interview with Sam Vincent and Jonathan Brackley about Series 10.

Watch the Series 10 trailer…