There's no compelling evidence that NSW man Matthew Leveson was killed by his boyfriend Michael Atkins before the older man buried his body in the Royal National Park, a Sydney inquest has heard.
Deputy State Coroner Elaine Truscott is on Tuesday hearing final submissions at the inquest into the death of the 20-year-old who was last seen leaving Darlinghurst's ARQ nightclub with Atkins in September 2007.
Counsel assisting the coroner, Tim Game SC, said that despite Atkins' many false accounts, there wasn't sufficient evidence to suggest his actions killed Mr Leveson.
The 54-year-old long denied any knowledge of Mr Leveson's whereabouts, but this year he led police to the 20-year-old's remains after striking a deal to avoid contempt of court and perjury charges.
He told police he decided to bury Mr Leveson in bushland south of Sydney after finding him dead from a drug overdose the morning after they went to ARQ nightclub.
Mr Leveson's parents believe their son could have died by strangulation or smothering, but Mr Game said on Tuesday there wasn't supporting forensic evidence or evidence of a struggle in Mr Leveson's Cronulla apartment.
He told the court there was "ultimately no reliable objective evidence" as to the manner and cause of Mr Leveson's death, and submitted that the coroner should make an open finding.
As they left Glebe Coroner's Court, Mark and Faye Leveson said they were hoping for the best but expecting the worst.
"It's upsetting, I know we'll probably get an open finding, but as Mark said, we've been knocked down that many times I'm not expecting things to go our way," Ms Leveson told reporters.
"The main thing was that we did find Matt, we got him back.
"If we get an open finding, we'll have to just live with that, but we know in our hearts who was responsible for it."
The inquest was adjourned on Tuesday morning and the coroner has reserved her findings.