The name and nature of Harris’ character has not yet been revealed, but on Instagram, Doctor Who showrunner Russell T Davies has called him “the greatest enemy the Doctor has ever faced.”

In the first-look photo, provided by the BBC, Harris is seen to be wearing an old fashioned apron with a pair of pliers among the tools in its front pockets.

The news comes in light of Sex Education star Ncuti Gatwa’s appointment as the new Doctor and Heartstopper breakout Yasmin Finney as Rose, as well as fan favourites David Tennant and Catherine Tate returning as the previous incarnation of the Doctor and Donna Noble.

Harris previously worked with Davies on the RTS Award-winning AIDS drama It’s A Sin.

“Thank you for inviting me into your Whoniverse, Russell T Davies,” said Harris on Instagram. “I’ll try my hardest to do my worst.

“This Doctor has no idea what’s in store. And Even if he does… Who cares? Ha ha ha HA ha-ha-ha!”

Davies himself added: “It’s my huge honour to open our studio doors for the mighty Neil Patrick Harris… but who, why, what is he playing? You’ll just have to wait.

“But I promise you, the stuff we’re shooting now is off the scale. Doctor beware.”

Doctor Who is now filming in Wales and will air in 2023 as part of the series’ 60th anniversary.