David Tennant has hinted that his former co-star Billie Piper could become the next Doctor.

And when asked on BBC Breakfast on Monday if Billie, who played his assistant Rose Tyler, could step up into the role, David said: “Why not?”

He said: “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 everytime.

“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.”

Last week the actor announced he will no longer be playing the Time Lord in the BBC’s long-running sci-fi hit Doctor Who.

It has also been reported that former EastEnders actor Tom Ellis has emerged as a candidate to take over from David Tennant, who is to step down from Doctor Who at the end of next year.

A BBC source told The Mirror: “Tom is the frontrunner for the job and is very interested.”

Ellis, who is married to Tamzin Outhwaite, played Dr Oliver Cousins in the BBC soap during 2006. Other names linked to the iconic role include Robert Carlyle, Paterson Joseph and David Morrissey.

Ellis previously appeared on Doctor Who in the role of Thomas Milligan.