Filming on David Tennant's final Doctor Who story has begun today with the return of the actor Bernard Cribbins.

Cribbins, who plays Donna Noble's grandfather Wilf, was last seen in the Series 4 finale, Journey's End and first appeared in Doctor Who in the 1966 film, Daleks' Invasion Earth: 2150AD.

The legendary actor was spotted on set in Tredegar House where Who has filmed a number of times, including most recently in The Next Doctor. Next week, the production team are heading to another familiar location - the house used for Donna Noble's home.

David Harewood, currently starring as Friar Tuck in BBC1's Robin Hood, confirmed on Jonathan Ross's radio show that he will also be starring in the two part finale, due to air over the Christmas period.

The first special, Planet of the Dead, is due to air April 12, with the first trailer being broadcast this Wednesday on BBC1.