The M3 in Hampshire is still closed in both directions after police were called to the scene at 4am this morning.
Of
ficers are working alongside the Explosive Ordnance Disposal team to make the motorway safe again.
However, the closure caused enormous disruption on Saturday morning.
Delays of over three hours were being reported by some motorists, who face miles of tailbacks due to the diversions being put in place.
The road closure is expected to cause major problems for thousands of Manchester United fans travelling south for their Premier League match at Southampton, Hants, at 3pm.
The M3 is completely closed between junction 9 and junction 11 at Winchester.
People were pictured playing golf, walking their dogs and generally trying to pass the time.
A spokesman for Hampshire Constabulary today said: “We are now in a position to provide further details to this morning’s incident on the M3 between junctions 9 and 11.
Police were called at 3.49am to reports of potential hazardous material in the road.
Our officers are working alongside partners from Hampshire Fire and Rescue Service and the Explosive Ordnance Disposal (EOD) team to establish exactly what it is.
Nobody has been hurt in the incident.
The road is still closed at this time, and we will endeavour to get the material cleared as soon as possible.
Thank you for your patience, and please keep an eye on our social media channels for further updates.
An ambulance hazardous response team also rushed to the scene this morning, which Hampshire Police would only describe as a serious police incident until 11.30am.
It led to scores of people taking to social media today to complain about the lack of information being given out about the road closure, and a failure to warn motorists getting onto the motorway who are now stuck in queues.
The chaos comes just days after the M1 was closed for nine hours in both directions after a suspicious package was discovered under a motorway bridge near Milton Keynes.
A bomb squad used a robot to investigate the item which was found to contain no explosives from where prior tests were.