Colum Regan

Colum Sanson-Regan was an actor who acted as David Tennant's body-double. He stood in for the Tenth Doctor during a scene of Voyage of the Damned, then played a significant role during Journey's End: in scenes where the Tenth Doctor and the Meta-Crisis Tenth Doctor were together, he and Tennant took turns playing the characters. (REF: End of an Era) He also played a Roman soldier in The Pandorica Opens and a Weevil in several episodes of Torchwood.