A man was attacked and robbed by a knifeman as he took cash out from a high street bank.
Police were called to a south London hospital after a 51-year-old man self-presented with a number of injuries, including lacerations.
Detectives established the man had been assaulted outside the Halifax on Rushey Green, Catford at 12.50am on January 14.
DC Alan Jones, from the South East BCU which covers Lewisham, said: “This was an unprovoked attack on a man in the street.
“Whilst we have made an arrest, I still need to speak with anyone who saw the assault.
“The victim has told us that there were other people in the area at the time, and I need them to come forward and tell me what they saw.”
The victim told detectives he had been punched by the suspect – who was known to him – whilst withdrawing money from a cash machine.
The suspect left but returned a short time later carrying a bladed article which he used in a second attack on the victim.
Later that afternoon, a 42-year-old man attended a south London police station and was arrested on suspicion of causing grievous bodily harm and robbery. He was subsequently bailed pending further enquiries.