Detectives from the East Midlands Serious Collision Investigation Unit are appealing for witnesses after the two-car crash on the A47 near Skeffington on Tuesday afternoon.
It happened at 4.09pm on Tuesday on the A47, Uppingham Road, Skeffington, about 400 metres east of the junction with Main Street, and involved two vehicles, a black Toyota Yaris and blue Peugeot 206.
The driver and passenger in the Toyota Yaris and the driver of the Peugeot 206 were taken to the Queen’s Medical Centre in Nottingham.
The male driver of the Toyota remains in a critical condition, said police, while the passenger in the Toyota and driver of the Peugeot, both women, are said to be in a stable condition.
Det Con 1761 Pete Davies, who is investigating the collision, said: “The Toyota was travelling along the A47 towards Uppingham and Peterborough and the Peugeot was travelling in the opposite direction when the collision occurred.
“We would like to speak to anyone who was travelling along the A47 in Skeffington at around 4pm on Tuesday, if you saw either vehicles beforehand or witnessed the collision then please get in touch.”
Three fire crews from Uppingham, Leicester’s eastern fire station and the heavy rescue unit from Oakham were called to the scene.
Both cars overturned and ended up in roadside ditches.
Anyone with information is asked to contact Det Con Davies on the police 101 number, follow the instructions to leave a message for the officer and when prompted key in the officer’s identification number 1761.
Alternatively, contact Crimestoppers, which is free and anonymous, on 0800 555 111.
Story by Alex Blackwell.