The Independent Office for Police Conduct has begun an investigation into a collision, following a short police pursuit in Staffordshire.
The IOPC says it is understands two cars overtook an unmarked Staffordshire Police car at speed on the A5, in the direction of Cannock at approximately 4am this morning (24 May).
They say the evidence they have at this time indicates police activated their blue lights and followed the cars.
A short time later, one of the vehicles, a white Volkswagen Scirocco, crashed into a roundabout at Longford Island and into the nearby DFS store.
Both occupants of the Volkswagen, two men, were ejected from the vehicle. They are now being treated in hospital for life-threatening injuries.
IOPC Regional Director Derrick Campbell said: “Our thoughts are with all those affected by this incident including the emergency services involved.
“We sent investigators to the scene and have begun to gather evidence, such as CCTV footage and statements from the officers involved, to help us get an early picture of what has happened.
“At this early stage there is no evidence to suggest that there was contact between the vehicles, but our investigation is still in progress.”