The Colony of Lies by Colin Brake

The Colony of Lies is a Doctor Who novel featuring the Second Doctor as they arrive at Axista Four in the year 2539. They find the colony in a state of chaos, with a civil war against the Realists and the Loyalists.

Meanwhile, a spaceship from Earth has arrived with news that 80,000 refugees are about to descend upon the planet; the Realists are staging raids on the wreck of the colony ship, and in a secret underground bunker mysterious aliens who claim to be the planet's first colonists are beginning to awake.

Who are the aliens who call themselves Tyrenians? What is the secret agenda of the sinister Federation Administrator Greene? And what really happened when the colony ship crash-landed on Axista Four 100 years ago?