Fleming (The Underwater War)

Mister Fleming was head of security on the Ocean Explorer, which was a submarine searching for special minerals on the planet of Hydron. He held a dark secret though. Rory discovered fish roe on the sub, which actually turned out to be a fuel source. Soon, when they've walked up the side of a water volcano, he took over as he finally revealed his plan to Rory and Jane Clancy. He was going to use the fish roe to make him rich. What some people didn't know was, that he had visited the planet before, inside the Marine Adventurer, but all the crew had been killed except for him. Escaping with the fish roe inside the submarine, he was almost away when the Eleventh Doctor saved the day. He was arrested and taken to the brig. (NSA: The Underwater War)