The Police Ombudsman's Office has appealed for information about the circumstances that led up to a fatal crash in Co. Derry/Londonderry on 16 March 2006.
Two men died when a Honda Civic car collided with three other vehicles near Castledawson, around 50 miles from Letterkenny, at about 9.20pm on March 16.
The Civic had been reported stolen from a car-park at Paddy Hart Road in Letterkenny earlier that day.
The men who died were Paul Mathews (26) from Poleglass, outside Belfast, and Damien McDonald (19) from the Ardoyne area of the city.
Some of the people travelling in the other vehicles sustained serious injuries and were treated in hospital.
Police in Northern Ireland had followed the Honda car prior to the collision. The Police Ombudsman investigates all fatal collisions in which police have been involved.
Investigators from the Police Ombudsman's Office would like to talk to anyone who saw or knows of the whereabouts of Mr Mathews and Mr McDonald in the hours prior to the crash.
They are particularly keen to hear from anyone who knows where the men were, between the time they finished work in Letterkenny on Thursday afternoon and the time of the collision. The men had been working in the town as double-glazing installers for the past few months.
A spokesman for the Police Ombudsman said: "We are keen to establish where the men went after finishing work, whether they met up with anyone else, and when they set out on their journey towards Belfast. The men's families are also hoping to establish the circumstances leading up to their deaths."
Anyone with any information is asked to call the Police Ombudsman's Office on 048 90 828653 / 828685 if ringing from the Republic Of Ireland, or 028 90 828653 / 828685 if ringing from Northern Ireland.