A man in his 20s remains in hospital after being stabbed in Peckham Rye Park on Sunday night.
The victim is believed to have been knifed in the back in the park before being found nearby in Upland Road, East Dulwich, by paramedics at around 9.42pm.
There have been no arrests. The investigation is being led by Central South Basic Command Unit detectives.
Anyone with information should call 101 quoting CAD 7524/21MAR21, Tweet @MetCC or call Crimestoppers anonymously on 0800 555 111.