Zeno (Doctor Who and the Day of the Daleks)

Zeno (PROSE: Doctor Who and the Day of the Daleks) was chief of internal human security and loyalist to the Daleks on an alternate 22nd century Earth.

Biography
He interrogated the Third Doctor shortly after he was captured by the Ogrons, but was sent away by the Manager.

After overhearing the Controller talking to the Doctor and Jo Grant about preventing the Dalek invasion of Earth and the Controller betraying the Daleks, the senior guard informed his masters of the Controller's treachery.

After the Daleks exterminated the Controller as a traitor, Zeno was made his replacement. However, the Doctor subsequently averted the timeline in the 20th century. (TV: Day of the Daleks)