Officers were called to Croydon Road after members of the public helped a man with stab wounds to his face at around 11.30pm on August 3.
The incident had reportedly happened outside Favourite Chicken in Beckenham High Street.
The man was taken to hospital where he remains with non-life threatening injuries.
No arrests have been made as police enquiries continue.
We understand the crime scene has since been lifted.
A spokesperson for Metropolitan Police said: “Police were called at 11.02pm to Croydon Road, Bromley after members of the public assisted a man with stab wounds to the face.
“The incident had allegedly occurred on Beckenham High Street.
“When they arrived on Croydon Road, officers alerted the London Ambulance Service.
“A man in his 40s was transferred to hospital, where he remains with non-life-threatening injuries.
“No arrests have been made and enquiries continue.
“If you have any information that could help police call 101 quoting CAD 7460/03Jul.”
