A coroner is examining the 1998 disappearance of Joanne Butterfield and the adequacy of the police investigation, led by three detectives over almost three decades.
The inquest has heard Ms Butterfield's landline made frequent calls to the number of a Cairns man named Victor Varga in the weeks before she went missing but police didn't follow that up until two decades later.
Lawyers are due to make submissions next month before Coroner Stephanie Williams considers her findings.
It took police more than 20 years to speak with a man who likely had frequent phone contact with missing Far North Queensland mother Joanne Butterfield in the weeks before she disappeared, a coronial inquest has heard.
Ms Butterfield was 37 when she vanished after leaving her Mossman home in late June 1998.
Her body has never been found and there are no signs she remained alive.
A coronial inquest examining her disappearance heard the landline at Ms Butterfield's home most frequently exchanged calls with a landline at the Cairns home of a man named Victor Varga, who has since died.
Ms Butterfield's telephone bill showed nine calls between her home and Mr Varga's from early May to early June 1998, the longest being half an hour.
Counsel assisting Peter Ah Gee has questioned why Mr Varga was not spoken to until after Detective Senior Constable Kevin Spies took over the investigation in 2019.
Senior Constable Spies, who has been excused from giving evidence at the inquest on medical grounds, had two conversations with Mr Varga, most recently in 2021.
Ms Butterfield was last seen hitchhiking south of Port Douglas and told relatives and acquaintances she intended to relocate to her home state of New South Wales.
The inquest has heard about a time Ms Butterfield hitched a ride to Cairns with Mr Varga.
Anthony van den Broek, who worked with Mr Varga and was the partner of his daughter, last week told the inquest he was in the car when Mr Varga picked Ms Butterfield up on their way home from a concreting job in Mossman.
Mr van den Broek recalled Ms Butterfield staying the night at Mr Varga's place before leaving the following morning, when he said Mr Varga tried to convince a "troubled" Ms Butterfield to stay.
A few weeks later, Mr van den Broek said he recognised Ms Butterfield on news reports about some of her property being found beside a cane railway near South Johnstone.
Mr van den Broek said he had no information about Ms Butterfield's disappearance, and it was not clear to him whether she and Mr Varga knew one another before she hitched the lift.
Mr van den Broek said he remained in infrequent contact with Mr Varga until his death a couple of years ago.
Homicide squad detective Senior Sergeant Glenn Kite said even if original lead detective Graeme Eaton did not identify Mr Varga, it "doesn't detract from the effort he did put in the rest of the investigation".
Senior Sergeant Kite told the inquest detectives had gone "above and beyond what you'd normally expect to see" in a missing-persons investigation.
Mr Eaton investigated Ms Butterfield's disappearance from July 1998 until 2002.
As Mossman's only detective at the time, his "large workload" included an investigation into the January 1998 disappearance of American tourists Tom and Eileen Lonergan who were unintentionally left behind during a scuba diving trip off Port Douglas.
Mr Eaton has previously told the inquest he attempted to recall specific enquiries he made 28 years ago.
Questions have also been asked during the inquest about why Ms Butterfield's discarded belongings were not forensically tested.
In 2019, Senior Constable Spies asked forensic scientists whether they could test for Ms Butterfield's DNA on an orthopaedic bone plate that had been found in the stomach contents of a crocodile in Rockhampton earlier that year.
"I know its [sic] been in a crocodiles [sic] stomach for maybe up to 20 years but, if the question is not asked, we could miss an opportunity," he wrote.
Police never excluded suicide or foul play as having caused Ms Butterfield's suspected death.
Coroner Stephanie Williams is due to hear statements from two of Ms Butterfield's children and final submissions from lawyers next month.