Williams, 23, appeared for sentencing in the Supreme Court at Albury before Justice Monika Schmidt. She imposed a head sentence of 21 years and nine months.

Williams will be eligible for release on January 15, 2026, after 16 years, three months and 23 days.

Justice Schmidt allowed a 25 per cent discount for Williams pleading guilty otherwise the whole sentence would have been 29 years.

Ms Wilkinson, 20, died on September 18, 2009, from blows Williams used a shovel to inflict. Asphyxiation contributed to her death.

Williams assisted the Volunteer Rescue Association to search for her after she was reported missing. He confessed to the murder after police gainedf a warrant to seize his two vehicles.

He took police to Dairy Lagoon near Corowa where Ms Wilkinson’s naked body was found lying face down about in a 60cm-deep grave.

Earlier, Williams had claimed Ms Wilkinson, who had been drinking on September 18, contacted him, He said they went for a drive before he had dropped her off.

Justice Schmidt said an autopsy showed no detectable alcohol or common drugs of abuse or prescribed drugs in her body.

Williams gave two explanations of why he murdered Ms Wilkinson.

First he claimed he had started to choke her as a joke and was unable to stop.

Later when interviewed by a forensic phychiatrist, he claimed he went into “a blind rage” when Ms Wilkinson said it was good his defacto partner had lost a baby a week earlier.

Williams, who Justice Schmidt said was socially gregarious with a close circle of friends, gave varying accounts of how much alcohol and cannabis he had used that night.

“The offender told police she was already dead when he struck her,” Justice Schmidt said.

“That belief appears to have been wrong, but the evidence certainly suggests that she was, by then, unconscious. She was patently defenceless.”

Justice Schmidt said Williams had denied any knowledge of Ms Wilkinson’s whereabouts and for several days took steps to conceal her death and his responsibility.

“His confession and subsequent co-operation with police reflected that remorse over what he had done, while initially absent, came to grow,” Justice Schmidt said.

“The offender gave conflicting accounts as to how much he had drunk and how he was affected when he killed Ms Wilkinson.

“It is apparent from his confession and actions in assisting the police that whatever his level of intoxication, he had a memory of what he had done to her.

“He concealed the burial site in such a way that even when he later took the police to the site, it was not apparent that the ground had been disturbed.

“He was able to conceive and act on a plan to conceal his knowledge of Ms Wilkinson’s death and the whereabouts of her body by disposing of her mobile phone and sending a text to her phone and attempting to ring her after her death.”

Justice Schmidt said Williams gave two quite different accounts of how he came to murder her.

“The evidence does not permit any firm finding as to what it was that triggered his attack,” she said.

“That this was a most brutal killing may not be overlooked in assessing the objective seriousness of the offence and the range within which it falls.”