An inquest has heard a crayfish farm worker borrowed a pump-action shotgun to carry on-site because he "feared for his life".
The Coroners Court of Queensland on Monday reopened an inquest into the death of Jeffrey Lawrence Brooks, who was shot through the chest in March 1996, while tending to crayfish ponds at a farm at Beenleigh on Brisbane's southern outskirts.
An inquest in 1998 returned an open finding, but Mr Brooks' family has campaigned for the coroner to revisit the case after rejecting a police finding of accidental death, claiming he was murdered.
The 24-year-old was found in the seat of a utility vehicle with a single-barrel break-action shotgun underneath his body.
"(At the original inquest) Jeffrey's father Lawrence outlined to the court the family's theory that Hans (Geiger) had killed Jeffrey, with the cooperation of Regine (Geiger) and Graham (Lloyd), because they believed he was a threat to the farm and their livelihoods," counsel assisting Sarah Lane told the inquest in Brisbane.
The three named people were employed at the farm while Mr Brooks was developing a feasibility study into the unprofitable crayfish operation.
Mr Brooks was required to use a firearm to scare off birds at the farm.
The coroner was told Mr Brooks was a highly experienced firearms user and had told his wife Nicole he needed to borrow additional shotguns because "the firearm on the farm was unsafe and that he would have something to defend himself if he was threatened by Hans".
Ms Lane told the inquest Jeffrey Brooks' brother David said he "had come to my home quite distressed, and asked if he could borrow my 12-gauge pump-action seven-shot shotgun. I asked why and Jeffrey said he honestly feared for his life."
Coroner Donald MacKenzie said the inquest would hear a lot of evidence, including testimony from 17 witnesses and a visit to the scene of Mr Brooks' death.
Mr MacKenzie approved an application from the Brooks family's solicitor to have the former lead police investigator, Mike Condon, who is now an assistant commissioner, excluded from parts of the hearing.
The solicitor said it would affect any cross-examination of Mr Condon about how he ran the investigation if he heard others testify.
The original inquest found Mr Condon's investigation to be "competent and thorough".
Outside the court, Mr Brooks' parents said they were relieved the inquest had been reopened.
"We're very excited to get to this point. We have tried for years to get to this point. There have been stops and starts but we are finally there," Wendy Brooks said.
"(Jeffrey) was such a wonderful guy and he deserves everything we have put in over the past 26-and-a-half years.
"(His death) has left a massive hole in our lives ... all we have ever wanted is truth and justice and we have felt for many years the truth has been suppressed."
Lawrence Brooks said his firearms testing, which disputed the police findings, was backed up by four other experts.
"Jeffrey was very safe with guns," he said.
The inquest continues.