Three men smashed Shaun Barker’s kneecaps and hands, bashed him with a golf club, kept him in a fishing esky and put honey on his testicles for ants to eat.

However, a court has now found that none of the trio meant him to die.

Barker’s remains were found charred and scattered in a remote area near Gympie, four months after he was kidnapped from the Gold Coast.

On Tuesday the court of appeal in Brisbane quashed William Francis Dean’s murder conviction but substituted it with a manslaughter conviction after finding there was no intention to kill Barker.

Dean’s co-accused, Stephen Armitage and Matthew Armitage, previously successfully appealed against their murder convictions, but were found guilty of manslaughter.

All three men were also previously convicted of torture, but will now be retried.

Accused of stealing $80,000 worth of the drug ice, Barker was taken to a Gold Coast house where he was punched, hit with a golf club, wrapped in carpet and had his hands duct-taped to his head on 10 December 2013.

He was later taken to the property near Gympie where he was kept in the esky.

Witnesses told the trial Barker’s kneecaps and bones in his hands were smashed, a finger cut off and honey put on his testicles for ants to eat while he was being held until around Christmas.

The events involved people who dealt in or used drugs, justice Philip Morrison said in his appeal findings.

Barker was reported missing in January, but it was not until April 2014 that part of his skull and jaw bone were found, followed by bone fragments and eventually more substantial parts of his skeleton.

Some burnt bones were found in a fire pit.

Morrison said Barker’s cause of death could not be determined and it was reasonable no one had intended to cause the death or harm.

“The evidence supported a finding that Barker was being held for the purpose of discovering where missing drugs or money were kept, the inference being that it was in the interests of all of the others to keep him alive,” Morrison said.