The 16-year-old victim told police she was walking near the intersection of Dunnings and Palmers Roads on December 9 when she was approached by a stranger.
Detectives say the man grabbed the teenager by the arm and walked with her for a short time while sexually assaulting her.
The suspect is described as being of Indian or sub-continental appearance, around 25-years old with a slim build, brown eyes and with black hair and beard.
He was wearing a black jacket and pants and told the victim his name was Sam.
Police have released a computer-generated image of a man they wish to speak to in relation to the asault, along with a still image and CCTV footage.
Anyone with information about the identityof the man is urged to call Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au