Lee Castleton was a Post Office sub postmaster, buying a post office in Bridlington in 2003. He was taken to the High Court by the Post Office when there were unexplained losses of £25,000, and was subsequently bankrupted when the Post Office pursued him for legal costs of £321,000. He is one of many Post Office sub postmasters who suspected the Horizon computer system was at fault and is now campaigning for justice, an apology, and compensation.