Detectives are appealing for information after a man was attacked at Purley train station.

The incident happened in the early hours of Friday, August 16, at about 2.30am and officers have released a CCTV image of a man they want to speak to in connection with the incident.

The victim and the suspect, who did not know each other, had been travelling on a train from London Victoria.

There had been some conversation between the pair and as they both got off the train at Purley, the suspect punched the victim a number of times.

The attack stopped when a member of the public stepped in to help the victim and the suspect ran from the station.

Detective Constable Helen Magill said: "As a result of the attack the victim was left requiring hospital treatment for a bleed on the brain, a chipped tooth and a bruised nose and eye socket.

"From our enquiries so far, we know that the suspect was travelling alone and could possible live in the Purley area.

"We are keen to speak with anyone with information about the incident and particularly the man who helped the victim during the attack."

Anyone with information should contact BTP on 0800 40 50 40 or text 61016 quoting background reference B6/LSA of 16/10/2013 or Crimestoppers anonymously, on 0800 555 111.