"It's not a single witness or a single piece of evidence that is the final piece of the puzzle; it all comes together to form a brief of evidence [for the court]," Superintendent Cook said.

"At the end of the day, I'd really like to thank the community for coming forward," he said.

Nobody has claimed the $750,000 reward for information.

"Some people aren't motivated by money; they are community minded," Superintendent Cook said.

Mr French, 39, did not apply for bail, which was formally refused by the court.

Ms Ardler's disappearance was handed to the unsolved homicide squad following a coronial inquest into her disapperance in 2016.

In May last year, a teenage boy found bones, later identified as belonging to Ms Ardler, in bushland in Laycock Street, Cranebrook. Her family had long suspected she was dead.

A $100,000 reward was then increased to $750,000.

"Today's news is a very bittersweet moment for our family," Ms Ardler's mother said in a statement issued after the court proceedings.

"It’s very hard to know that our beautiful Cheryl will never be coming home and that she was so cruelly taken from us.

"Cheryl’s smile could light up the room and her love for life was infectious.

"She is so loved by all of us and without her here, our family just won’t be the same."

Mr French is due to appear before Penrith Local Court again on June 7.