A 'suspicious vehicle' was seen outside Marne Barracks at Catterick Garrison hours before a reported explosion in the early hours of this morning.
The A1 was closed for more than 12 hours after staff at the North Yorkshire army barracks reported hearing an explosion around 3am.
North Yorkshire Police say they have worked overnight and throughout the day to locate the driver of the vehicle and rule him out of any connection to the alleged explosion.
Officers say they are now satisfied he was not related to this investigation and he has been eliminated from their enquiries.
Supt Hannan also thanked drivers for their 'patience and understanding' during long delays on the A1, adding: "Their safety was our primary concern."
Police have reopened the A1 in North Yorkshire after it was closed for more than 12 hours following reports of an explosion.
It was shut between Leeming and Barton as a precaution while police investigated reports of a blast near Marne Barracks at 3am this morning.
Eight people told police they heard an explosion - but officers say after extensive searches of the area, they've found no obvious signs of a blast.
North Yorkshire Police, the North East Counter Terrorism Unit, explosives detection dogs, the National Police Air Service and military search personnel have all been involved in today's searches.
Police investigating reports of an explosion in and around CatterickGarrison says they have found a number of ageing detonators alongside the A1 adjacent to Marne Barracks.
These detonators are being removed by the army’s bomb disposal team to a safe area where a controlled explosion will take place.
However a police spokesman insists that the detonators were NOT the cause of the original explosion reported by staff at the Marne Barracks at 3am.
The search for the source of that explosion continues and the police say that the A1 will reopen when it is safe to do so.
The road has been closed in both directions in the Catterick area since 3am.
A spokesman for the Highways Agency said the closure on the A1 in North Yorkshire is now expected to remain in place until between 5.30pm and 6pm.
Earlier today they had anticipated that the road would re-open at around 3pm.
Police are continuing the search for the source of an explosion reported by staff at the Marne Barracks, in Catterick, at 3am.
Police say they still haven't managed to locate the site of an explosion close to Marne Barracks in Catterick.
Staff at the Barracks reported hearing an explosion around 3am, but the search for where it happened has been hampered by darkness and poor weather.
The search remains focused on the area outside of the barracks and the area next to the A1 although police they can't rule out the possibility it happened within the boundary of the barracks.
Extraordinary images of an empty A1 at Catterick have been taken by ITV News Tyne Tees. On what is expected to be one of the busiest shopping days of the year, the A1 motorway is closed in both directions as police investigate reports of a possible explosion in the Catterick Garrison area.
The Highways Agency says it expects the A1 around Catterick garrison to remain closed until around 3pm.
Police have closed the A1 in both directions in North Yorkshire after reports of a possible explosion in the Catterick Garrison area.
North Yorkshire Police say a report was received at 3am Saturday after an explosion was heard in the Catterick area. There are no reports of any injuries at this time.
Both slip roads to Catterick have also been closed and diversions have been put in place.
Motorists are advised to avoid the area at this time.
A police spokesman says this is a precautionary measure while police conduct their enquiries.