Tennant: 'Billie could be the next Doctor'

David Tennant has suggested that Billie Piper could end up as his Doctor Who replacement.

When asked by BBC Breakfast if Piper, who played the Doctor's assistant Rose Tyler on the cult show, could land the coveted role, he replied: "Why not?"

Referring to the birth of Piper's son Winston, Tennant added: "I think she's busy breast feeding at the moment but I'm sure she'll bounce back before long."

The 37-year-old noted that the part of the Doctor is open to a diverse range of actors.

"It's one of those parts that any actor could bring something valid to, because it can be anything and it's a sort of blank canvas every time," he said.

"The fact is that the difference is a virtue with each Doctor. It's not like you're casting Tarzan where you've got to have somebody who looks good in a loin cloth - it can be anything."

> Russell Tovey talks Doctor Who