The cause of death for Emma Faulds could not be established, murder trial jurors were told.
Pathologist Dr John Williams carried out a post-mortem examination on the 39-year-old’s body.
Ms Faulds’ remains had earlier been discovered within Glentrool Forest in Dumfries and Galloway on June 12, 2019.
However, Dr Williams said the corpse being so decomposed “limited” what could be concluded.
Ross Willox, 41, is accused of murdering Ms Faulds at his home in Fairfield Park, Monkton, Ayrshire, on April 28, 2019 by means unknown and then dumping her body.
Dr Williams was taken through his findings by prosecutor Paul Kearney at the High Court in Glasgow on Friday.
Jurors were shown graphic photos of Ms Faulds’ remains during the post-mortem.
The pathologist said he could not be “definite” as to when Ms Faulds died.
Other details included within the report were that she had no fractures to the arms, legs or ribs.
There was also no “significant natural disease” detected.
Mr Kearney asked the witness: “So nothing to point to a natural cause, but, with the great caveat, your examination was affected by the state of decomposition?”
Dr Williams replied: “That is right.”
The trial heard there was evidence of cocaine and alcohol from samples taken from Ms Faulds.
Reading from his report, Dr Williams stated: “In summary, the medical cause of death has not been established.
“The degree of decomposition has limited many aspects of the post-mortem.”
Advocate depute Mr Kearney asked, as a result, the cause of death must be ruled as “unascertained”.
Dr Williams responded: “Yes.”
Willox denies the accusations.
The trial, before judge Lord Mulholland, continues.