Hampshire Police are appealing for witnesses of the incident which brought the M3 to a near 12-hour standstill yesterday.

Official information has now been released that the “potential hazardous material” which was attended to by police and partners including an Explosive Ordnance Disposal Team, is not being treated as a terrorist incident.

Police were called to the road at 3.49am, and found a flammable material, not explosive material, was thrown from the motorway bridge which leads to St Catherine’s Hill.

Assessments are being continued into the material, but officers are urging there is no wider risk to public safety.

Thousands of motorists were caught in gridlock as the incident led to a full closure of the M3 junctions nine to 11, until approximately 3.30pm on Saturday.

No-one was hurt from the incident.

Officers are also investigating a similar incident which took place on the same bridge last week at around 4am on Saturday 16 September.

An object was dropped from the carriageway and a quantity of glass was found but no fire.

Lane 1 was closed for a short time to clear the debris and there were no casualties.

Police are urging anyone who witnessed either incident or who has any information to contact them immediately on 101.