Doctor Who star Freema Agyeman joins Sex and the City prequel

Former Doctor Who star Freema Agyeman has been cast in the upcoming Sex and the City prequel, The Carrie Diaries.

She will play Larissa in the new TV show, a character described as a "hip, cutting-edge editor/party girl" who works at Interview Magazine, reports Deadline.

Larissa will act as something of a mentor for the young Carrie Bradshaw, who will be played by AnnaSophia Robb in the pilot episode for US network CW.

Agyeman was Tenth Doctor David Tennant's companion Martha Jones in Doctor Who from 2006 to 2010, and also appeared as the character in Torchwood in 2008.

She has since become a regular face on ITV1's Law & Order: UK, playing solicitor Alesha Phillips.

The Carrie Diaries is being developed by Gossip Girl producers Josh Schwartz and Stephanie Savage, and is an adaptation of author Candace Bushnell's 2010 novel, which pre-dates the events of Sex and the City.

Actors Austin Butler, Katie Findlay, Stefania Owen and Ellen Wong have also been cast in the new show.