Detectives are appealing for anyone with dash cam footage to come forward following a collision on the A1 in Barnet.
Police were called at 21:33hrs on Monday, 13 January to the A1 southbound, between Stirling Corner and Apex Corner, after a dark coloured Audi collided with a lamp post.
The three occupants - three men, all aged in their 20s - were all taken to hospital.
Their injuries are not thought to be life-threatening, though one of the passengers may have suffered life-changing injuries.
Road closures were put in place whilst emergency services dealt but have since been re-opened.
Detectives from the Serious Collision Investigation Unit are leading.
They are looking at whether any other vehicles may have been involved in the incident.
They would like to hear from anyone who may have dash cam footage of the incident, or who may have witnessed it.
Anyone with information is asked to call the SCIU on 02082469852
Alternatively tweet @MetCC or call 101, quoting ref CAD 7421/13 Jan.