The police began investigating wardens and prisoners at Ashmoret prison on Friday to find out who came in contact with the prisoner Yoni Alzam who died mysteriously on Monday in the jail, hours before he was meant to testify in the murder trial of Shimon Zirhan. No signs of violence were found on Alzam's body, but an acrid-smelling chemical substance was found in his cell. The police believed that the most probable cause of his death was poisoning. The High Court of Justice permitted an autopsy despite the early objections of Alzam's family. In addition to investigating the cause of death, police will also try to determine whether the prison services failed to perform their job properly, according to Israel Radio. Before his planned testimony, Alzam was held in isolation for his own protection.