AN ARMED robbery suspect escaped custody while receiving treatment at hospital yesterday. Frederick Green, 29, made his escape from the Princess Margaret Hospital's chest ward after the prison officer assigned to him left to use the bathroom. Green, alias Frederick Neely, was remanded to Her Majesty's Prison after he was charged with two counts of armed robbery. According to police, he had no prior convictions. In a press statement yesterday, HMP maintained that the officer secured Green in restraints before leaving to use the restroom. However the accused was gone when the officer returned. The police and the prison's internal affairs unit are investigating. The last prisoner to escape from PMH was 28-year-old Dorian Ambrister, on December 13. Ambrister was serving a 27-month sentence for stealing from a shop. Although he was outfitted with leg restraints and on 24-hour guard, he escaped the healthcare facility by jumping through a bathroom window. Ambrister was shot in the buttocks by prison officers on Dowdswell Street a short time later. Inquiries placed to Superintendent Elliston Rahming over whether the latest escape has sparked possible changes to security measures for prisoners receiving medical treatment were unreturned last night. Green is a former resident of Carmichael Road and was described to have a medium build, dark brown skin, and height of 5ft 11ins. Anyone with information that may assist in Green's recapture should contact police at 919, the Criminal Detective Unit at 502-9991, or Crime Stoppers at 328-TIPS.