The Police Ombudsman's Office is appealing for witnesses to an incident which took place near Toomebridge on 8 April 2011.
Just after 6.00pm on the Moneynick Road, heading towards Toomebridge, an incident involving a police vehicle and red BMW occurred which resulted in the BMW coming to rest on a grass verge at the side of the road.
"We would like to hear from any witnesses in the area at the time, particularly passing motorists, who may be able to help us find out what caused the vehicle leave the road," said a spokesman for the Office.
Anyone with any information is asked to call the Police Ombudsman's Freephone Witness Appeal Line on 0800 345 7106.