The young man who fell from a police vehicle in Maghera, County Derry/Londonderry last week has died in hospital.
He was Paul Somerville, who was 21 years old and lived in the town.
He was being treated for critical head injuries received during the incident, which happened on Friday afternoon.
The Police Ombudsman's Office is investigating the circumstances of what happened.
It has renewed its appeal for anyone who was in the Maghera at lunchtime on Friday and who saw what happened to contact them.
Investigators are particularly keen to hear from anyone who saw the police van as it drove along the Crew Road, Station Road and Church Road areas of the town at around 1.20pm.
The number to call is 0800 032 7880.