Media playback is unsupported on your device Media caption Dr Who companion, Jenna-Louise Coleman, had a brief discussion with the Queen, in which they talked about time travel

Doctor Who star Jenna-Louise Coleman has admitted filming her final scenes opposite Matt Smith will be an emotional experience.

"I don't even want to pick up that script just yet!" she said in one of her first interviews since Smith announced he was leaving the BBC show.

She insisted she has no idea who will play the next Doctor.

The actress was speaking after meeting The Queen at the official opening of the BBC's Broadcasting House.

Coleman, who plays the Doctor's assistant Clara, said it was "such an honour" to meet Queen, and that she was the only person who did not try to quiz her about the identity of the next Doctor.

"Everybody else in the building has asked me who the next Doctor is, and I can tell you honestly we don't know. It's going to be a long, long search. But yes, I'm being asked that question a lot."

She confirmed that filming on Matt Smith's final story will not begin until the autumn. The special episode, which will be broadcast at Christmas, is also expected to introduce Smith's successor.

Image caption Jenna-Louise Coleman plays Doctor Who assistant Clara alongside Matt Smith

She said she has no preferences for what kind of actor will be cast.

"I am completely open, and I have lots of confidence in [head writer] Steven [Moffat] and all the team. And I'm sure they're very much across it. But we shall see.

"I just can't think about it yet. I think because we've [Matt and I] got so much left to [do]. We haven't even begun our goodbye yet. So, I suppose that's all I can think about at the moment.

Since Matt Smith announced that he was leaving the BBC One show after four years there has been a large amount of speculation about his replacement.

At the moment the BBC will only confirm that the search for the 12th actor to play the Time Lord is now under way.

When and how the new Doctor's identity will be revealed is likely to depend on when an actor is chosen.

With filming for the Christmas special not beginning until the autumn, a casting announcement may not need to be made until late summer, or even later.

When Matt Smith was chosen as the 11th Doctor, the news that someone had been cast and their identity was successfully kept secret for weeks.