A grandmother who was playing with her grandson on a nature strip has allegedly been sexually assaulted by a man who asked her for cigarettes.
The 66-year woman repeatedly told the man she did not have any and walked away with her grandson.
The man then approached the woman from behind and sexually assaulted her while he made crude comments, police said.
The incident happened in the Melbourne suburb of St Albans about 2.50pm on December 16.
The woman and her grandson were at the intersection of Alfreida Street and Craiglea Avenue.
The woman shouted at him before he walked off on Craiglea Avenue then up Collins Street, he then doubled back down Collins Street and walked back down Craigielea Avenue towards View Street.
Brimbank Sexual Offences and Child Abuse Investigation Team detectives are appealing for public assistance to identify the man.
Police said the offender was perceived to be of African appearance, approximately 175cm tall with a slim build, a mark on the left side of his cheek and protruding teeth.
He was wearing a black and white varsity jacket, a brown cap, black shirt, and dark-coloured skinny jeans.
Police have asked anyone with information to contact Crime Stoppers