A second man has been arrested in connection with a car crash that killed three teenage boys after he handed himself in to police.
A 34-year-old man was arrested on suspicion of causing death by dangerous driving after handing himself in at a north London police station at around 7pm on Sunday.
Investigators had appealed for the whereabouts of the man, believing there were at least two men in a black Audi that ploughed into three friends on Shepiston Lane in Hayes.
The Metropolitan Police said formal identification of the victims had yet to be completed, officers were confident they are Harry Rice, 17, and 16-year-olds George Wilkinson and Josh Mcgunniess.
Despite the efforts of paramedics, all three boys were pronounced dead at the scene.
It is understood they had been on their way to a birthday party at a nearby football club with friends when they were killed.
Detective Sergeant Michael Rapp, of the Met's serious collision investigation unit, said: "Earlier today, police released images of a man they wish to speak to in connection with this incident.
"A man has now handed himself in at a police station and been arrested before being taken into custody for questioning. I would like to thank the media and public for their assistance with this appeal.
"This is a fast-moving investigation and CCTV inquiries and forensic analysis of the car involved are under way.
"At least two males are believed to have left the black Audi A5 following the collision.
"Inquiries are ongoing to establish the full circumstances of the collision and the number of occupants in the vehicle involved."
He also appealed for privacy for the families, who were "still barely coming to terms with their loss".
The victims were with a group of friends walking towards the Goals five-a-side football club at around 8.40pm on Friday when they were hit.
The collision occurred close to the Esso garage near junction four of the M4.
The Met said: "The vehicle involved is believed to have been travelling at high speed and came to a stop a short distance away from the collision."
A 28-year-old man was detained by members of the public and has been arrested on suspicion of causing death by dangerous driving.
The first suspect remains in police custody.