Two motorists have been arrested on suspicion of causing death by dangerous driving after a motorway collision.
A man in his 20s was pronounced dead at the scene on Saturday morning after a crash involving a silver Vauxhall Vectra and a grey BMW 1 Series.
Three other men, including the driver, needed hospital treatment, the Metropolitan Police said.
Officers were called at around 12.50am, police said. The family of the dead man have been informed.
A 22-year-old woman driving the BMW was arrested on suspicion of causing death by dangerous driving and taken into custody.
The driver of the Vectra, a 24-year-old man, was arrested on suspicion of causing death by dangerous driving and driving while disqualified.
One man travelling in the Vectra remains in critical condition while the conditions of the driver and another male passenger are not thought to be life-threatening.
Any witnesses or anyone with dashcam footage of the collision or the moments beforehand is asked to call police on 101 or the witness line at Chadwell Heath Traffic garage on 020 8597 4874, quoting reference300/08jan.