The Sainsbury Centre for Mental Health is investigating the impact of powers allowing judges to lock up prisoners indefinitely.

More than 3,000 offenders are on imprisonment for public protection orders. The research will examine how many of those subject to the orders have mental health problems and whether they are receiving adequate care. It follows a report by the Forum for Preventing Deaths in Custody showing that 600 people a year die in custody, which Mr Bell said demonstrated the need for better primary mental health care in prisons.