Inspector Morse: Absolute Conviction (1992)

Lawrence Cryer is a fraudster serving a sentence in a minimum security prison.The initial cause of death was thought to be a heart attack but the autopsy reveals he was struck down. Cryer was one of three businessmen who had defrauded millions from would be investors. His fellow fraudsters, Alex Bailey and Brian Thornton, are serving their sentences in the same prison. Cryer's young widow is now having an affair with Thornton's son and Bailey continues to engage in financial planning of some sort. Morse believes that the three must have salted some money abroad but is having difficulty finding the evidence. When a second fraudster collapses from an overdose of heart medication, Morse focuses on those who lost money in the investment scheme but the answer lies elsewhere.