Accused double murderer Greg Lynn has described a "horrendous" crime scene after a struggle over a shotgun that he claims led to the death of two missing campers.
The 57-year-old former airline pilot said he told police the truth "at all times", as he took the witness stand four weeks into his murder trial before a Supreme Court jury in Melbourne.
He has pleaded not guilty to two counts of murder over the deaths of Russell Hill, 74, and Carol Clay, 73, in the Wonnangatta Valley, in Victoria's northeast, in March 2020.
The court's upstairs public gallery had to be closed as it became full before Lynn gave evidence on Thursday morning.
He is the defence team's only witness, after prosecutors finished their evidence on Wednesday.
Lynn's wife Melanie and one of his sons, along with the family of the two deceased campers, were among those watching in court.
After he was sworn in by a court associate, defence barrister Dermot Dann KC asked Lynn a series of questions about what he told police.
"Did you attempt to tell the truth at all times?" Mr Dann asked.
"At all times," Lynn calmly replied.
"At the time of the discharge, I was struggling with Russell Hill for control of the shotgun," he told the jury.
"I was aware of her (Mrs Clay), she was over there ... She would have had to be crouching or kneeling."
He raised his arms to a "motorcycle grip" as he described how he was trying to get the gun back off Mr Hill.
"Russel Hill had his back towards the bull bar (of the vehicle) and I was pushing him against the bull bar," he said.
Lynn said Mr Hill slipped and the gun moved to his left and Lynn's right. "At that angle the discharge went through" the car's side mirror and then into Mrs Clay.
He said he was trying to get the gun back off Mr Hill, whom he claims had taken it from his vehicle - one of two guns Lynn took to go deer hunting that weekend.
"I don't know if he intended to shoot me, probably not, I think he was trying to keep the shotgun for himself and scare me off," Lynn said.
He told police Mr Hill later came at him with a knife, and another struggle ensued leading to Mr Hill's death.
"There was a large pool of blood on the ground," Lynn said.
"The scene was horrendous."
The jury was earlier in the week played Lynn's police interview, where he also set out his version of events.
Mr Hill had threatened to show police drone footage of Lynn hunting deer near their campsite, he told officers.
Once he realised they were both dead, he used his experience as an airline pilot to formulate a plan to "save" himself.
That included moving the bodies to remote bushland of the Union Spur track and then going back in November 2020 to burn the remains.
The trial continues.
