The actions of the claimant will not be treated as a novus actus where the duty of care on the defendant requires them specifically to prevent the claimant from taking such an action. In Reeves v MPC [2000] 1 AC 360, the House of Lords decided that the Metropolitan Police were under a duty to ensure that a prisoner, who was a known suicide risk, did not take his own life while he was in their custody. As a result of failings by the custody officers, the prisoner was able to kill himself. The House of Lords held that a successful argument that the prisoner’s action amounted to a novus actus would, in effect, remove the impact of imposing the duty of care on the defendant.