Shocking CCTV footage of a man dying on the floor of a police station surrounded by officers will be shown on prime-time television tonight in a bid to uncover the truth about his death.

Christopher Alder, a former paratrooper, died in Queens Gardens station in Hull on April 1 1998. His family, who want a full public inquiry, believe his death had racist overtones and was, at best, negligence and, at worst, manslaughter.