Doctor Who fans are about to be whisked into a parallel universe – with another spin-off series from the hit sci-fi programme.

The Torchwood-style offshoot will be based on UNIT, the military research organisation introduced in the 1960s.

Jemma Redgrave, 58, will star as head of scientific research Kate Stewart, a role she has played since 2012.

Created by showrunner Russell T Davies, the new series will be part of the expanded Whoniverse created by the BBC’s deal with Disney+ to take it worldwide.

UNIT – or Unified Intelligence Taskforce – first appeared in 1968 under second Doctor Patrick Troughton. The organisation, which investigates paranormal and extraterrestrial threats to Earth, got a fleeting mention in 2005, post-reboot, before becoming more key.

Jemma – a member of the Redgrave acting dynasty – has starred alongside Matt Smith, Peter Capaldi and Jodie Whittaker.

Kate and her team will return in a festive special introducing 15th Doctor Ncuti Gatwa, 30, before the offshoot launches.

A source said: “Doctor Who has always featured strong women in positions of authority.” A monsters spin-off is also planned, it has emerged.

There had been talk of creating a spin-off show featuring UNIT in the 1970s, but this came to nothing.

However UNIT continued to appear throughout the Jon Pertwee years from 1970-74, and also featured in a handful of stories with Tom Baker until 1981.

After the reboot in 2005, the organisation was first given a fleeting mention in Aliens of London, with Christopher Eccleston, before being given a full return alongside David Tennant in The Sontaran Stratagem in 2008.

Prior to Gatwa’s arrival as the 15th Doctor, Tennant will be returning in three specials to mark the show’s 60th anniversary this year.