Search for new Doctor Who's partner begins

The producers of Doctor Who have begun the search for a "high profile" female companion after unveiling little-known actor Matt Smith as the new Time Lord.

Smith, 26, a surprise choice for the 11th Doctor and the youngest actor ever to take the role, is largely unfamiliar to audiences and BBC bosses are keen to pair him with a showbusiness name.

The singer Lily Allen is an early favourite, while sources say Strictly Come Dancing stars Rachel Stevens and Kelly Brook are high on the BBC's wish-list.

Producers are looking for someone who is famous outside the world of acting – replicating the success of former Doctor's assistant Billie Piper, who was better known as a teenage popstar and the wife of DJ Chris Evans when she landed the role but proved a hit with viewers.

Auditions will take place over the coming months and filming begins in the summer. Piers Wenger, executive producer of the BBC One show, said: "Having got the casting of the Doctor out of the way, the companion role is where we will be looking next.

"Someone terribly exciting like Billie Piper, who was at the beginning of her acting career but who had a profile for other reasons, would be great. We are looking for someone whose light can burn brightly."

Allen, 23, was linked with the role once before, but it went to comedienne Catherine Tate. She is a favourite with bosses at the BBC, where she has her own chat show, and is keen to try her hand at acting. She would follow in the footsteps of singer Kylie Minogue, who was cast as the companion in the 2007 Christmas special.

Wenger said: "We would never cast anyone on the basis of their celebrity, but if Lily wanted to audition we would be delighted. It would be a lot of fun."

Brook, 29, has acting experience, including a remake of the Italian Job, but has never had a major television role. Doctor Who sources say her name has come up in discussions several times. She will face competition from Stevens, 30, who is keen to carve out a screen career and recently took acting lessons in Los Angeles. Model Agyness Deyn, 25, is another possible choice.

All are close in age to Smith, who takes over from David Tennant in 2010. Nearly seven million viewers tuned in to BBC One on Saturday to discover the 11th Doctor's identity.

There had been much talk of a black Doctor Who, with actor Paterson Joseph among the favourites. Wenger disclosed: "We saw a dozen or so people, some of them black. There was never any resistance to the idea of a black Doctor and it would have got us all sorts of headlines and brownie points, but we set out to cast the best actor for the role irrespective of ethnicity or age, and that was Matt."