Accused police killer Jason Roberts' lawyers say transcripts of secret listening devices made by police decades ago are significantly less incriminating when translated by experts.
Roberts is facing a fresh trial over the murders of Sergeant Gary Silk and Senior Constable Rodney Miller in 1998, after a previous conviction was quashed by Victoria's Court of Appeal earlier this month.
Defence lawyer Peter Matthews says they've spent tens of thousands of dollars already having expert linguists redo transcripts of the "indistinct" recordings used in Roberts' original 2002 trial.
Original recordings were transcribed by police.
"The content is significantly less inculpatory when transcribed by an expert, to the point of not inculpatory at all," he said in a Supreme Court bail application by Roberts on Thursday.
In overturning the conviction, three Court of Appeal judges said the prospect of Roberts being convicted again was not inevitable, but the prosecution case remained strong.
Mr Matthews said that was not necessarily the case, when considering the evidence as it would be presented in a fresh trial.
Another trial, estimated to take three to four months, is likely to happen late in 2021 or early in 2022, Justice David Beach said.
But Mr Matthews said preparation alone in the case could take 12 months or more.
The defence team has also spent a significant sum of money on expert scientific reports, including around the evidence about whether there was one or two shooters involved.
Roberts has admitted - and will maintain in a fresh trial - that he was involved in a series of robberies with Bandali Debs, who was also convicted of murdering Sgt Silk and Sen Const Miller.
Roberts has always maintained his innocence in the murders. Debs is serving a life sentence and has not appealed.
Mr Matthews said another aspect of the new trial will be the fresh defence evidence about an alibi, from both Roberts and his then-girlfriend Nicole Debs - the daughter of Bandali Debs.
He said the fact alone that he had spent 20 years behind bars after a trial "corrupted" by Victoria Police was exceptional enough in itself to justify bail.
Roberts has been in restrictive custody since 2013 and coronavirus restrictions in place since March this year had compounded the weight of imprisonment on him, Mr Matthew said.
Prosecutor Ben Ihle SC said there were ultimately three factors for Justice Beach to consider.
"In favour of the grant of bail is clearly the considerable period of time the applicant has already spent in custody," he said.
But on the other hand he said Roberts was facing extremely serious allegations and their belief it was a strong case.
Roberts denied at his first trial, but has since admitted, that he was involved in 10 burglaries with Debs, that he used a 0.38 handgun in those robberies and he continued to offend with Debs after the officers died.
Mr Ihle acknowledged the time Roberts had spent in custody was significant, but he was coming up against an undeniably strong or powerful prosecution case.
Justice Beach acknowledged that if Roberts was to be convicted and receive the same sentence, he would have only have served a fraction of it.
