A robber attacked a teenager and then set his dog on him when he failed to to steal the boy's phone.
The boy, 16, was walking in Mulgrave Road on his way home from a friend's house when a man with a Staffordshire bull terrier-type dog approached him from behind and threw him to the ground at around 9.30pm on Friday, December 14.
The attacker tried to grab the teenager's mobile phone but failed and decided to set his dog on the boy.
The would-be robber then left empty handed with his dog in the direction of Sutton leaving the boy with cuts, grazes and bruises. An ambulance was called but the teen did not need hospital treatment.
The suspect is a white man, aged between 18 and 25-years-old, of slim build and about 6ft tall. He was wearing light blue jeans, white trainers and had a white cap or hood over his head. He was with a large, brown dog, possibly a Staffordshire bull terrier.
Police are appealing for anyone who saw the attack or thinks they may know the suspect to come forward. If you have any information you can call Sutton's burglary and robbery investigation team on 020 8649 0777 or the charity Crimestoppers on 0800 555 111.