RACHEL Penno has spent three years agonising over what fate befell her only child when he disappeared on New Year's Eve, 2017.
On Tuesday the NSW Hunter Valley mother told a Cairns inquest, into the sudden disappearance of her son Jayden "Jay" Penno-Tompsett, that she believes he was murdered.
"I believe he's been murdered," she said. "I know he's been murdered."
Ms Penno said police told her Jayden was travelling from Newcastle to Cairns with $10,000 worth of drugs to meet friends for a New Year's Eve party, and on the way he smoked half and lost the other half.
She said Jayden had recently lost his job in demolition and she understood he had bought the drugs on "tick".
"Jay was carrying drugs, $10,000 worth, he smoked half of it...and lost the other half of the drugs," Ms Penno said.
Jayden vanished from the remote Far North Queensland town of Charters Towers in the early hours of December 31, 2017.
The court heard that while police believe Jayden perished in the harsh conditions outside Charters Towers after having a fight with his travelling companion Lucas Tatersall and storming off on foot, Ms Penno does not agree.
Ms Penno said in the months before Jayden went missing he had been threatened.
She told the court she accessed his social media accounts after he disappeared and there were "guns, drugs and money owed". The court heard Jayden started using methylamphetamine (ice) on-and-off from the age of 16 and it caused him to have "mood swings" and become "irrational and angry".
He was described as normally having a "beautiful" and "gentle" nature that changed when he was using drugs.
Ms Penno described trying to take Jayden to the Mater Hospital, at Waratah, in the weeks before he disappeared due to concerns about his mental health, but said he jumped from the car and ran off because he didn't want to be admitted.
She was the first witness to give evidence in Cairns Coroners Court on Tuesday morning and said she believed her son had met with foul play.
The court heard of a serious rift between Ms Penno and investigating police, who she said refused to keep her informed of progress in the investigation.
The court heard the rift started after Ms Penno released information on social media that the police had asked her to keep confidential.
"He's probably run off with a Swedish backpacker and they had a chuckle to themselves...," Ms Penno said police told her the week after Jayden vanished.
"I don't really know much of the investigation. I don't see that there is much investigation gone into it."
Ms Penno said police had not followed up on several lines of enquiry and it took "ten months" to interview the man Jayden bought the drugs off.
But Detective Sergeant Edwards told the inquest that Mr Tattersall's story fitted with what the police investigation uncovered and Jayden had a history of going off alone after a fight.
"I believe he wandered into the bush, in the matter of what people reported he may have done, and he has perished in the bush," he said.
Queensland Coroner Nerida Wilson is determining whether Jayden is dead, and if so, when and how he died.
An emotional Ms Penno broke down when counsel assisting the coroner Joseph Crawfoot played CCTV video of Jayden and Mr Tattersall stopped for fuel at a Charters Towers roadhouse.
The grainy video is the last known footage of Jayden alive.
Throughout the video, just hours before Jayden disappears, he can be seen frantically searching through the car with the torch on his mobile phone, looking for the lost drugs.
Ms Penno said she believed there was a physical altercation in the car between Jayden and Mr Tattersal over the missing drugs before the pair left the roadhouse.
She said in the months leading up to the trip to Cairns there was a "war going on between Jay and his mates" over money and drugs.
"They're young....this is what they do, they go out on the weekend and get on the pingers [ecstacy]," she said.
"This is what they do, playing around with these nasty drugs."
The court heard Ms Penno had not had enough time to read the police's 170-plus page running sheet on their investigation and was excused from giving evidence to further review the document.
She may be recalled to give further evidence on Wednesday.
The inquest continues.