Jodie Whittaker isn't allowed to reveal the length of her 'Doctor Who' contract.

Jodie Whittaker as Doctor Who

Jodie Whittaker as Doctor Who

The 35-year-old actress has become the first woman to play the time traveller in the BBC sci-fi series, but she has now revealed she cannot tell anyone how long she will be playing the titular character for.

Asked about the length of her deal in a longer version of the Sunday Times' recent interview with Jodie - which has been published on Chrissy Iley's blog - she said: "I am not allowed to answer that."

Jodie made her debut in the festive special in December and will appear later this year for the full series alongside Mandip Gill, Tosin Cole and funnyman Bradley Walsh.

The actress has taken over the role from Peter Capaldi - who played the Doctor for four years - while Chris Chibnall has become the new show runner following Steven Moffat's exit.

Jodie has admitted it was "completely overwhelming" to be the first female Time Lord.

She said: "It feels completely overwhelming; as an actor, as a woman, as a feminist, as a human, as someone who wants to continually challenge themselves and not be boxed in by what you're told you can and can't be.

"I want to tell the fans not to be scared by my gender because this is a really exciting time and 'Doctor Who' represents everything that's exciting about change. The fans have lived through so many changes and this is only a new, different one, not a fearful one."

Despite her excitement, Jodie has insisted she didn't feel daunted when she auditioned for the part.

She said: "I went to the audition excited, but I always walk into the room with an attitude of 'I sound like this, I look like this, but, believe me, I can do it'."