Stelpor

 was part of the Ormelian security service. He wanted to destroy Vilgreth. He told the Seventh Doctor about the dangers of Vilgreth including how he was created. He sacrificed himself to delay Vilgreth so the Doctor could escape the ship they were on and destroy it. (AUDIO: Last of the Titans)

Behind the scenes
Stelpor originally appeared in the Audio Visuals story of the same name, voiced by Alan Lovedale.