Cecilia Devine,41,was reported missing from Waratah,near Newcastle,in September 2018.
"We believe Cecilia’s death is suspicious due to the nature of where she was located and how she was located,"Blue Mountains Police Area Commander Detective Sergeant James Allan said."She wasn’t wearing any clothes and we haven't been able to locate any of her belongings."
The mannequin,dressed in a yellow cardigan,grey shirt and black pants,also carries a wig that mirrors the 41-year-old’s"distinctive blonde hair"and an orange handbag,Sergeant Allan said.
"Friends and family have described her as being vivacious,caring and outgoing."
"We’ve established some strong leads into Cecilia Devine’s disappearance and death in recent months but there are still many unanswered questions,"he said.
He said while police had already received"some"help from the public,they are"hoping for more and that's the purpose for the display and having the mannequin wearing what Cecilia was when she was last seen".
An autopsy had been performed but the results have not been released.
Anyone with information that may assist police investigations is urged to contact Crime Stoppers:1800 333 000
with the