Prosecutors have been unable to prove the death of a former bikie gang boss due to a lethal injection of cocaine and heroin was murder.
A close friend of Ricky Ciano and fellow ex-Rebels bikie, Jamie Tozer, pleaded guilty to manslaughter on Wednesday after a court accepted there was not enough evidence to prove the drugs were administered without consent.
Tozer had been due to face a murder trial in the NSW Supreme Court.
Ciano joined the Rebels in 2001 when he was 20 years old and went on to become president of the Liverpool chapter, in southwest Sydney.
He left the group in 2015 and several close supporters, including Tozer, went with him.
The men, along with Tozer's half-brother Daniel Bushell, travelled to a property in Oberon, in the NSW Central Tablelands, in February 2017 with a plan to manufacture drugs.
At some point while they were at the property, Ciano was injected with a cocktail of drugs that included cocaine and heroin - a mix known as a "speedball" - and died soon after, according to an agreed statement.
His body was found three days later in his BMW, which was parked on a nearby road.
Bushell administered Ciano the fatal shot after being supplied the drugs by Tozer, the documents said.
Bushell was initially charged with murder but was found not guilty by a jury in 2023 and convicted on the lesser charge of manslaughter, receiving a nine-year jail sentence.
Prosecutors put forward evidence suggesting Ciano would not have consented to taking the drugs, including calling heroin "disgusting" and "junkie s***", according to his wife and sister.
Ciano happened to be stopped by police while on his way to the Oberon property, during which he returned a negative breath test and did not appear to be under the influence of drugs or alcohol.
It was also put forward that during a course of intravenous therapy in 2010 Ciano, who was heavily tattooed, appeared to be afraid of needles.
But the court also was told Ciano had become a regular user of the opioid oxycodone before his death and previously injected growth hormones and steroids.
In the weeks leading up to his death, the ex-bikie increased his use of oxycodone tablets, which he had also taken on the day of his death prior to the injection.
Ciano was also known to drink and use cocaine recreationally, and used the prescription drugs diazepam and the opioid tramadol.
"(Ciano's) family were unaware of the extent to which the deceased was using opioid medication," the documents said.
"The Crown cannot establish beyond reasonable doubt, and therefore do not contend, that the deceased did not consent to the injection."
Tozer is due to return to court for a sentence hearing on April 4.
