'I have always said I would love to return to the Whoniverse.' Billie Piper appears to be the new Doctor in shock twist as Ncuti Gatwa exits the TARDIS

Billie Piper has been "revealed" as the new Doctor, although the credits mysteriously didn't call her the Time Lord.

In the Doctor Who season finale "The Reality War", Ncuti Gatwa regenerated into Billie’s apparent new Doctor.

The hugely popular star famously played companion Rose Tyler as the sidekick to the Ninth and Tenth Doctors, Christopher Eccleston and David Tennant.

Billie, assuming she’s confirmed as the Doctor, is the second woman to take on the iconic role after Jodie Whittaker played the 13th Doctor.

Speaking of her return, Billie says: "It’s no secret how much I love this show, and I have always said I would love to return to the Whoniverse as I have some of my best memories there, so to be given the opportunity to step back on that TARDIS one more time was just something I couldn’t refuse, but who, how, why and when, you’ll just have to wait and see."

Speaking of the surprise twist, Russell T Davies adds: "Billie once changed the whole of television, back in 2005, and now she’s done it again! It’s an honour and a hoot to welcome her back to the TARDIS, but quite how and why and who is a story yet to be told. After 62 years, the Doctor’s adventures are only just beginning!”

Why did Ncuti Gatwa leave?

Speaking of his decision to leave, Ncuti said: “You know when you get cast, at some point you are going to have to hand back that sonic screwdriver and it is all going to come to an end, but nothing quite prepares you for it. This journey has been one that I will never forget, and a role that will be part of me forever. There are no words to describe what it feels like to be cast as the Doctor, nor are there words to explain what it feels like to be accepted into this iconic role that has existed for over 60 years and is truly loved by so many across the globe.

"The fans are truly the final character and beating heart of this show and I can’t thank the Whoniverse, and the Whovians, enough for welcoming me in, and making this such a touching experience. I’ve loved every minute of it, but now is the time to hand over the keys to that beloved blue box and let someone else take control and enjoy it every bit as much as I have. I’ll truly miss it, and forever be grateful to it, and everyone that has played a part in my journey as the Doctor.”

It's not currently clear when Doctor Who will return.