The last man involved in the brutal killing of Adelaide man Michael Purse has been sentenced to life in prison, nearly five years after the 32-year-old vanished in what prosecutors described as a cold and calculated murder.

Mark-Bry Leedham, 29, was found guilty of murder in April following a lengthy trial in the South Australian Supreme Court.

On Thursday, he was sentenced to life behind bars with a non-parole period of 28 years.

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He becomes the final of three men held accountable for Purse’s 2019 death.

Purse was last seen on February 7, 2019, at Adelaide Casino before being taken to a unit in Kilburn, where he was tied to a chair, beaten, and fatally stabbed.

His body was later dumped at an unknown location in Adelaide’s northern suburbs. Despite extensive police searches, his remains have never been found.

Leedham’s co-accused, David Graham Young and Edwin James Hinrichsen, both pleaded guilty to the lesser charge of manslaughter in 2023 and are currently serving 11-year sentences.

During the trial, the court heard harrowing details of the attack.

Hinrichsen, under the influence of methamphetamine, was said to have jumped on Purse’s chest while he was restrained.

Young and Leedham then took turns beating him, with Leedham ultimately delivering the fatal stab wound.

The two men later disposed of the body, which has never been recovered.

An extensive search of a property north of Adelaide in 2020 failed to uncover either the remains or the murder weapon.

Justice Kevin Nicholson condemned Leedham’s refusal to accept responsibility, telling the court the convicted man had shown no remorse and had offered no assistance in recovering Purse’s body.

“It shows a profound failure to take responsibility for your actions,” Nicholson said.

“You say that you have shown no remorse, and provided no cooperation, because you have been convicted of an offence that you did not commit.”

Leedham has since lodged an appeal against his conviction.

Purse, who was known to be involved in Adelaide’s drug trade, had previously committed theft and fraud to fund his addiction. His family reported him missing in April 2019, and police declared his disappearance a major crime in June that year.

Despite his criminal history, Purse’s murder — and the fact that his body has never been found — shocked the community and prompted a years-long investigation that eventually led to the conviction of all three men.