The NSW Coroner has delivered an open finding into the death of Matthew Leveson.
Mr Leveson, 20, was last seen in the early hours of September 23, 2007, when he left an inner Sydney nightclub with his boyfriend Michael Atkins.
Mr Atkins, 54, continued to claim as recently as last year that his former lover was alive and could be living in Thailand.
However, he then led police to Matthew's skeletal remains in an unmarked grave in the Royal National Park in May 2017.
He told police he did not kill Matt, but panicked and disposed of his body after he died of drug overdose.
On Tuesday, Deputy State Coroner Elaine Truscott said Matt's family had been "tireless" in their quest for justice in the 10 years since their son disappeared.
She recommended they be given an official police commendation after they wore a wire in 2008 to speak to Mr Atkins.
During the conversation, Mr Atkins admitted he had lied to police about a mattock he bought at Bunnings.
The family asked if Matt died of a drug overdose, but Mr Atkins said his boyfriend had been "careful" with his doses.
The conversation was so distressing for Faye Leveson that she had to vomit in Mr Atkins' bathroom.
Ms Truscott said the conversation was significant, because it was a "direct contradiction" to Mr Atkins' later claims of an overdose.
"It is shocking that the Levesons had to endure that experience," Ms Truscott said.
"I do not accept Mr Atkins as a witness of truth.
"The lies he has told do not allow me to make a finding that any act performed by him caused Matt's death."
Supporters and family of Mr Leveson began to sob when the open finding was delivered.
Speaking on the steps of Glebe Coroner's Court, flanked by police investigators, the family wore purple ribbons and wiped away tears.
Mark Leveson said justice had been done "in a small way," and he believed the Coroner had gone as far as she legally could.
"She named Michael Atkins over and over and over again," he said. "His lies, his deception.
"Because of his deception and cover-up for so long, Matt's been in the ground for so many years now, when he was finally found there wasn't much there to test."
Faye Leveson said the family had been forced to choose between justice and finding their son's body, after Mr Atkins was granted immunity for the evidence he gave at the inquest, and immunity for perjury charges in return for leading police to Mr Leveson's remains in the Royal National Park.
"Sadly, we were forced into this corner," Mrs Leveson said. "And Matty comes out first every time."
Mr Atkins was acquitted of the murder and manslaughter of Matthew Leveson in 2009.