An ambulance service still can not find a computer disk containing details of 42,000 patients which has been lost for at least two months . An investigation has now been completed , but East Midlands Ambulance service ( Emas ) has been unable to work out how the disk went missing or where it could have gone . The Information Commissioner 's Office is still making enquiries and could fine Emas up to 500,000 . Emas has apologised to patients . Following the publication of the investigation report , Emas chief executive Sue Noyes said : " We are an open , honest and transparent service , which learns from its mistakes and takes actions to minimise the risk of such an incident happening again . " Emas noticed the disk was missing from a " secure storage safe " at its administrative site in Beechdale Road , Nottingham , on 14 August . They could not find it , despite what the investigation report describes as " extensive searching at the premises " . ;