A three-day search for the remains of missing schoolgirl Quanne Diec in bushland at Cataract ended on Wednesday, with nothing found.
Police began the search on Monday, using machinery to dig up an area of dense bushland off Appin Road.
Investigating police examined aerial photographs of the site from 1998 and today to learn how the landscape has changed over time.
The operation was part of an ongoing quest to find the body of the 12-year-old, who was allegedly murdered almost two decades ago.
This week’s search follows an earlier investigation at Bulli Tops last year, which failed to locate her body.
Quanne went missing on July 27, 1998 after leaving her Granville home to catch the train to Strathfield Girls' High School.
Vinzent Tarantino, 49, was charged with her murder in November.
Quanne’s father, Sam Diec, visited the Cataract search site on Monday.