Strike Force Amias investigators and specialist forensic officers searched a new area of Lester State Forest on Tuesday, about 20km south-west of Coolamon, where they found the skeletal remains.

While the remains are yet to be formerly identified, Riverina Police District Commander Superintendent Bob Noble said the circumstances strongly indicated they belonged to Ms Boyd.

In February 2020, Samuel John Shephard was sentenced to 27 years' jail for Ms Boyd's murder and drug offences, with a non-parole period of 20 years and eight months.

"The principal accused [Shephard] in this case assisted police yesterday after he was released on a section 25 order under supervision of corrective services officers and accompanied our detectives to the area," Superintendent Noble said.

"Ultimately, it was this information that he provided yesterday which led police to the discovery."

Superintendent Noble said there was nothing to suggest that Shephard, wasn't acting on "sincere motives".

"This is the second occasion [Shephard] was taken out to assist police and we are very pleased he was able to lead us to the right spot this time," he said.

"I did have a brief conversation with him, and his reasons are his reasons.

"There was certainly no arrangement made between police and the accused, but we leave no stone un-turned when seeking information, and this was just one source we worked on."

In 2017, detectives from the Riverina Police District established Strike Force Amias to investigate the circumstances surrounding Ms Boyd's suspicious disappearance and suspected murder.

Since that time, hundreds of official and unofficial searches of the forest have been conducted by police with no success until now.

Superintendent Noble said the discovery was of great relief to police and Ms Boyd's family, but the case was not yet closed.

"The remains will go off for forensic examination and hopefully a positive identification to that of Ms Boyd," he said.

"Investigators have been in touch with her family, and whilst they are very pleased with the breakthrough and appreciative of the efforts of police, they await the formal identification of those remains.

"The identification will obviously take some time, but I imagine they will do so as quickly as they can."

Police say the remains were found approximately 30cm underground, in a location which Superintendent Noble said was "close to the area" of the most recent search on November 30.

"We were indeed out in the forest only a couple of weeks ago with some earth-moving equipment, and it turns out we were very close to this location where the remains have now been found," he said.

"It is just illustrative of how difficult looking for remains or evidence in an area that is remote and not well marked can be."

A report will be prepared for the information of the coroner.