Rusterholz in 2015 was convicted of the murders of Angela Hallam, 31, and Joshua Newman, 21, in August 2012.

The couple was stabbed multiple times and their throats cut in Ms Hallam’s Ravenswood unit.

Their bodies were then set alight.

Rusterholz was sentenced to 45 years’ jail for the murders with a non-parole period of 25 years.

It had been argued that he committed the murders to square-up a drug debt and to impress his girlfriend Sally Maher.

The 2015 trial heard Rusterholz had shown Ms Maher and another man, Brett Imlach, Ms Hallam’s hair in a bag and a boot she was wearing at the time of the murder.

It also heard two other men, David Morgan and Matthew Coventry, had motives to kill Ms Hallam.

The appeal pointed to admissions by Mr Coventry, aired in the trial, that he had committed the murders.

Rusterholz’s lawyer Fabiano Cangelosi stated that Justice Robert Pearce had erred by failing to direct the jury that the state prosecution had to exclude the possibility that Mr Coventry’s admission was true.

He also pointed to DNA evidence belonging to Mr Morgan found on a blood-stained fuel container at Rusterholz’s home.

Mr Cangelosi said the verdict was therefore unreasonable and could not be supported with regard to the totality of evidence.

He said without the admissions, the circumstantial evidence was not enough to support guilty verdicts.

But this was dismissed by a panel of three judges: Justices Stephen Estcourt, Michael Brett and Helen Wood.

Justice Brett said the trial had heard from multiple witnesses that Rusterholz had admitted to committing the murders and destroyed evidence.

“The fact that the evidence did not necessarily exclude an involvement by Mr Morgan in the murders, in particular, does not less the weight of the evidence inculpating the appellant as the person who struck the fatal blows.”