A murder convict in Hajipur jail was killed in a clash between two groups of inmates Monday. The post-mortem report Tuesday confirmed that the prisoner was strangulated. The jail administration had claimed he died under mysterious circumstances. Bihar CM Nitish Kumar has asked Inspector General of Police prisons Anand Kishore to probe the incident. The incident took place Monday afternoon when Rambalak Roy,42,serving life sentence for killing his wife,got into a clash with a group of prisoners.