Investigators set up a crime scene at a second property at Bungonia after spending days searching dams and paddocks at another site in the area outside Goulburn, close to 200km southwest of Sydney.
Police on Tuesday confirmed that human remains had been discovered at the second property more than a week after Jesse Baird, 26, and boyfriend Luke Davies, 29, went missing from Sydney.
The two men were allegedly murdered in the inner-city suburb of Paddington by serving police officer Beau Lamarre-Condon, 28, on February 19.
Lamarre-Condon, who briefly dated Mr Baird, allegedly twice attended a property at Bungonia after the double killing, once with an acquaintance who was unaware of the murders and a second time to move the men's bodies.
Police on Tuesday began hunting an area deep in the sprawling Royal National Park as they tried to find the bodies and other evidence linked to the killings.
Investigators also said canvassing was continuing at Grays Point, in southern Sydney.
NSW Police Commissioner Karen Webb earlier said divers have finished their exploration of dams at Bungonia, but officers were still conducting a line search in the area.
"We still believe that there is possibly evidence in that area that we don't want to miss," she told ABC Radio.
Detectives believe the senior constable could have dumped the men's bodies at the Southern Tablelands site, before returning later to move them to another, unknown location.
Ms Webb said the crime scene was being treated as "anywhere between Newcastle and Bungonia and to the south of Sydney".
"It is a massive area and without co-operation it is just old-fashioned police work to work through every single lead and every single piece of information to try and locate Jessie and Luke for their family," she said.
Police are searching an area "between Newcastle and Bungonia and to the south of Sydney". (Mick Tsikas/AAP PHOTOS)
Lamarre-Condon has been exercising his right to silence after receiving legal advice.
The senior constable is accused of using his police-issued firearm in the killing before disposing of the couple's bloodied items in a skip bin at Cronulla, not far from Grays Point.
Police earlier on Tuesday confirmed a triple-zero call was made from Luke Davies' mobile phone, rather than from Mr Baird's phone as previously reported, four minutes after neighbours heard gunshots at the Paddington house.
A patrol car was later sent searching for the source of the call, which was disconnected before anyone spoke.
But officers were unable to locate the user and did not attend Mr Baird's house at the time.
Investigators allege the crimes followed a months-long campaign of "predatory behaviour" by the charged officer, culminating in the fatal shooting.
Mr Baird's friend Isaac Muller said the former TV presenter and Lamarre-Condon were never in a relationship, but the pair were "never going out".
Police believe Luke Davies and his partner Jesse Baird were shot dead. (HANDOUT/NSW POLICE)
Police allege Lamarre-Condon acted alone but divulged "partial admissions" to others before handing himself in, having travelled more than 1000km from Sydney to Bungonia and Newcastle in a rented van during his attempts to cover up the crimes.
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