The M1 has re-opened but delays remain in both directions following a 'police-led incident'.
Officials closed the road northbound and southbound between Junction 14 at Milton Keynes (A509) and Junction 15 at Northampton (A45/A508) earlier today.
The carriageway was initially closed on the northbound side at around 10.40am, with the southbound carriageway subsequently being closed at just after 11am.
The closure was lifted shortly before midday, but delays remain on both sides of the motorway.
National Highways resources are on the scene to assist with traffic management.
Traffic is queueing back to J13 for Milton Keynes South on the northbound side and back to J16 for Daventry on the southbound side.
A diversion route was in place via the A509 (H5 Portway), A5 and A508 with motorists being advised to expect delays.
It is not yet known what the nature of the incident was. MKFM will provide further information as we get it.