A police inquiry was launched after five people died early today when a car pursued by officers drove the wrong way up a motorway and crashed into another vehicle.
The Independent Police Complaints Commission (IPCC) will examine the circumstances surrounding the collision, which happened shortly after 3am on the M4 in Newport, south Wales.
A red Ford Mondeo travelling in the wrong direction had been pursued by Gwent Police beforehand, and collided with a red Volvo 940 on the eastbound carriageway between junctions 24 and 25.
Three men in the Mondeo were pronounced dead at the scene along with a couple driving a red Volvo 940.
The only survivor of the crash, an 18-year-old man travelling in the Mondeo, is in a critical condition at the Royal Gwent Hospital with multiple fractures.
Tom Davies, IPCC Commissioner, said: "It has emerged that at around 3am this morning a marked police vehicle had reason to try and stop a car containing four male occupants.
"Early indications are that the vehicle being pursued took a turn on to the motorway in the wrong direction. The police vehicle did not follow it. Some one and a half miles down the motorway, the fatal collision occurred.
"Both Gwent Police and South Wales Police road traffic investigators are co-operating with our team who have been at the scene since the early hours of the morning."
A spokeswoman for Gwent Police said the pursuit followed an incident in Penhow, which is between Caldicot and Newport.
She said: "Gwent Police can confirm that the road traffic collision that occurred at around 3.15am this morning was linked to an earlier incident at Penhow, where the force had cause to attempt to stop a vehicle on the A48, after it was made aware of suspicious activity.
"A short pursuit ensued and, as confirmed in the IPCC's earlier press release, when the other vehicle entered the M4 in the wrong direction, the Gwent Police traffic car halted this pursuit."
She added: "Gwent Police offers its sincere condolences to the families of all the deceased following this terrible tragedy and will continue to work closely with the IPCC in support of their investigation."
The motorway closure between junctions 24 and 28 in both directions caused traffic jams several miles long in and around the city.
Congestion was eased when the westbound carriageway was finally opened at around midday and the eastbound carriageway was opened about an hour later.
As part of their investigation, the IPCC has issued an appeal for any witnesses to the crash.
A spokesman said: "The IPCC want to speak to anybody who saw a red Ford Mondeo travelling in the wrong direction on the eastbound carriageway of the M4 between junctions 24 and 25, near to the Christchurch Road motorway bridge at approximately 3.15am."
"The Red Mondeo collided with a Volvo carrying two people.Reuse content