Police were called at 9.43pm on Saturday, 29 April to Manor Road, Beckenham, following reports that a man had been attacked.
A short time later, officers were informed that a 20-year-old man had presented at the hospital with head injuries – he remains there in critical condition. His family are aware.
A 17-year-old male was arrested at the scene on suspicion of GBH; he was taken into police custody and has been bailed pending further enquiries.
A crime scene is in place and enquiries are ongoing, led by the South Area Command Unit CID.
Anyone who witnessed the incident, or has information, video or images that could help police, should call 101 or tweet @MetCC ref CAD 8860/29 Apr.
To remain 100% anonymous contact the independent charity Crimestoppers on 0800 555 111.
