The drivers of two of four vehicles involved in a suspected multiple hit-and-run in which a woman died have been traced by police.
It is thought she was then struck by another lorry and two cars, and officers said none of the drivers stopped at the scene.
The 49-year-old man who was driving the first lorry to hit the victim in Tulse Hill on Monday morning has since been traced and interviewed under caution, the Metropolitan Police said.
The 52-year-old driver of the second car has been released under investigation after his arrest on Tuesday evening on suspicion of causing death by careless driving.
Officers are still working to trace the drivers of the two other vehicles.The victim has not been formally identified but her family has been informed.
A post-mortem examination revealed her provisional cause of death to be from multiple injuries.
Police have appealed for witnesses and anyone with dashcam footage to come forward.
The junction has been described as "a racetrack of sorts" by one resident, in a letter to Streatham MP Chuka Umunna.
In a joint statement with MP for Dulwich and West Norwood Helen Hayes, Mr Umunna urged anyone with information to come forward.
They added: "Lambeth Council is working closely with Transport for London on urgently needed changes to the Tulse Hill gyratory which will make it safer for pedestrians and cyclists.
"We are pushing for these works to be delivered as soon as possible, and for any lessons which emerge from the investigation into this appalling incident to be acted upon immediately."