The 24-year-old victim was returning to her Little Lonsdale St home around 3.30am on Saturday, August 3 before being followed into the elevator by a man.
Investigators have released CCTV images of a man who they believe can assist with their enquiries (above).
The man is perceived to be Asian with black hair and around 163-165cm tall.
He was wearing a dark-coloured zipped hoodie and a white baseball cap with “WEST” in black font written on the front at the time.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au