Judith Anne Young almost certainly died in "suspicious circumstances" and her estranged husband whose evidence to police contained "troubling aspects" should remain "a person of interest", Deputy State Coroner Sharon Freund has found.

In handing down her findings on Thursday Ms Freund said that detectives from the unsolved homicide squad should continue their investigations.

Ms Young was last seen on December 5, 1999 when she bought a Palamino mare and then drove the horse back to the home she shared with Mr Young in the tiny town of Gunningbland, 25 kilometres west of Parkes.

Ms Freund said that the 40-year-old had gone by a number of aliases prior to her death when buying and selling horses, selling raffle tickets for charity organisations and managing country music bands.

"Unfortunately, it seems that many of Ms Young's "business" interests and dealings were unsuccessful and some of them could be described as less than honest, even fraudulent," Ms Freund said.

Although there was no proof that the woman was dead, Ms Freund found that there was strong evidence which pointed in this direction.

In particular, records show that Ms Young was about to receive a substantial insurance payout following a horse fall some months earlier, but after December 1999 she made no attempt to claim the money.

Furthermore, after this time the 40-year-old did not use her medicare card despite needing medication to manage the ongoing head and neck pain that resulted from her accident.

Ms Freund also found that, as a lover of horses, it was completely out of character for Ms Young to abandon her horses and other animals in the way she did.

"Having considered all the evidence before me I am satisfied on the balance of probabilities that Ms Young is no longer alive and she died sometime after 5 December 1999," Ms Freund said.

At the same time, there were a number of suspicious circumstances surrounding Ms Young's disappearance and likely death.

Shortly before her disappearance, Ms Young had asked to borrow $680 from Michael Dean, telling him that she needed the money urgently because someone was going to kill her, but refusing to indicate who.

Mr Young said that he and his wife had decided to split up and that she had decided to move to Queensland.

He claimed to have spoken with the woman at least six times since she left, but could not remember the dates.

He also told police that they would probably not have much of a chance of finding Judith and that they didn't need to find her.

"As far as he was concerned Judith was happy and still alive, a position I note that he has maintained," Ms Freund said.

In July 2002, a year after Ms Young had been reported missing, Mr Young faxed a statutory declaration in the name of Judith Young to her younger brother.

The declaration indicated that Ms Young would forego all her entitlements as a wife to Mr Peter Young upon separation or divorce.

"It stated that she would leave the marriage with only a car, dog and personal property and that she would not make any claim to property or investments," Ms Freund said.

"It further stated that a second statutory declaration was made and sent to the State Bank to allow Mr P Young access to all her financial transactions and any further compensation claims."

She said there remained "troubling aspects" in relation to the evidence Mr Young provided to police that "does not sit with other evidence heard during the course of this inquest".

"Accordingly, he remains a person of interest in relation to Ms Young's death," she said.