Thames Valley Police are appealing for information after a highly corrosive substance was left on the M1 near Newport Pagnell forcing the closure of the road for most of yesterday.
Hundreds of cars and lorries were trapped on the motorway while the bomb squad investigated a container filled with acid-like liquid found under a bridge.
There is no suggestion the incident was terrorist related but the police want to know how it got there.
"We are appealing to anyone who knows why or how this object was left under a bridge about two miles past the Newport Pagnell services on the southbound carriageway of the M1. The object Is a 5 litre container in a large black refuse bag which found at about 7.30am yesterday. The object has now been removed from the scene in a secure container but is still being analysed, however, we do know the substance it is a highly corrosive material, possibly hydrochloric acid, which has reacted with another substance causing it to discharge onto lane one and lane two of the southbound carriageway. We are keeping an open mind as to how the object was left at the scene but at this stage we are investigating the incident to see if it was placed there with intent to cause danger to other road users. Anyone with any information about the incident, including any motorists who may have dash cam footage of the object being left at the scene, are urged to contact Thames Valley Police by calling 101." >