A LORRY driver may hold vital clues to an horrific motorway pile-up which left 24 people injured, police believe.

Detectives are appealing for public help to track down the man as they continue a criminal investigation into the crash which caused chaos on the A1(M) as the big Easter get-away started on Good Friday.

The 60 vehicle pile-up near Boroughbridge, North Yorkshire, occurred in thick fog at about 6.13am on the northbound carriageway.

A 16-mile tailback built up as 600 vehicles were left stranded on the carriageway as police carried out a detailed examination of the scene.

Officers are investigating three separate accident scenes.

North Yorkshire Police said they were treating the pile-up as a criminal investigation due to the "serious driving offences" committed.

The pile-up began moments after a caravan overturned and the vehicle towing it crashed into the central reservation.

Several lorries then ploughed into the wreckage as the motorway was turned into a scene of chaos as cars and lorries collided with each other.

Sergeant Brian Trickett said: "Something has gone on ahead of the caravan driver, we know that from markings on the road.

"Somewhere among the initial accident a green-coloured Volvo or Scania skip lorry has been involved."

He added that officers had found debris at the scene which indicated the lorry had been struck from behind.

"That vehicle has not stopped and the driver has carried on his journey. It is possible the driver didn't know. However, it is important we speak to him and eliminate him from our inquiries," he said.

Sgt Trickett said he was disappointed drivers had not heeded the advice issued after four people were killed in crashes in fog on the M5 and the M40 at the start of the Easter getaway.

Police said three pregnant women were caught up in the accident, although all escaped the carnage unscathed. Reports that a woman had gone into labour as a result of the pile-up could not be confirmed on Sunday.

The most seriously injured included a six-year-old girl, who needed surgery for internal injuries, and a 30 year-old man who suffered head injuries.

Sgt Trickett added: "From the sheer number of vehicles involved this was one of the worst accidents we have had to deal with. In terms of injuries, it was a miracle no-one was killed."