Velile Tshabalala has spoken to DigitalSpy about her role in this year's upcoming Christmas special, The Next Doctor.
"She's a proper feisty Cockney girl," said the actress, who plays the other Doctor's companion, Rosita, in the special. "She gives as good as she gets. She's very much on the good side, she's very loyal and she's got a strong relationship with the other Doctor.
"She added: "Oooh! I'll tell you a secret... we don't want to offend any of the children watching but she was actually a lady of the night [before the met the other Doctor]! She wasn't up to much good before, so thank goodness the other Doctor came along and gave her something a bit more constructive to do!"One night she was out earning her living and a Cyberman came to attack her.
The other Doctor came to rescue her and it went from there. He wasn't a client, he came and saved her!"You can read the full interview here. The Next Doctor will air on Christmas Day on BBC One at 6pm.