Ashley Walters has confirmed that he will be appearing in a Doctor Who episode next year and has already filmed his scenes.
The musician and actor recently filmed in Cardiff and admitted that he got into trouble for tweeting a photograph from a trailer.
He revealed: "I'm sworn to secrecy - I don't want to be killed by the Doctor Who police!
"I can't tell you anything about Doctor Who. I wasn't even allowed to tweet pictures or anything, I was really upset about that.
"I did tweet one picture in my trailer and I got in huge trouble with the producers on my first day so I'm not saying anything any more about it. But it was amazing working with Matt Smith for a few weeks."
Ashley is most known for appearing in the BBC's show Hustle in 2007.
[Source: Press Association (UKPS)]