Two people were taken to hospital after a police van and a Porsche collided, leaving the van on its side.
The van, which was carrying two Barnet Police officers, collided with the sports car near the junction of Totteridge Lane and Northcliffe Drive, shortly before 2.15pm.
A London Ambulance Service spokeswoman said a man and a woman in their twenties were taken to St Mary’s Hospital in Paddington for treatment.
A third crash victim was checked over at the scene, but did not require further treatment.
Barnet Police is yet to confirm whether those injured were police officers.
The collision caused major damage to the police van, while the Porsche, similar models of which are sold brand new from £70,000, looked likely to be written off.
Totteridge Lane was closed between Barnet Lane and Southway while the scene was cleared, Transport for London said.
James Varecka, who witnessed the aftermath of the crash, wrote on Twitter: “Police van on Totteridge Lane smashed to pieces.
“Van flipped sideways across road. Windscreen caved in. Porsche opposite with bad damage to the front.”
The crash is being investigated by the Metropolitan Police.
Yesterday, another police van was involved in a large-scale accident in Bermondsey, central London, after it catapulted over a car, leaving five people injured.