POLICE are trying to trace a good Samaritan who helped a man who had been attacked and knocked unconscious.

The 43-year-old victim was opposite The Dorchester pub in Bevois Valley Road by its junction with Lyon Street when he was hit on the head from behind.

The victim already had stitches in his head from a previous injury.

When he came to he was being helped to his feet by an elderly woman.

The attacker was black and about 5ft 2in with bad teeth.

Officers are now trying to trace the woman who helped him to his feet as she could be a vital witness and may have seen what happened.

Anyone with information about the crime, the woman who helped the man or anyone who knows who she is asked to call Detective Constable Scott Spafford at Bitterne Police Station on 101 or call Crimestoppers on 0800 555 111.