Greg Lynn, 56, was set to face trial on two charges of murder in the Victorian Supreme Court in October this year.
But his barrister Dermot Dann KC on Thursday raised funding issues in the case and asked that the trial date be pushed to 2024.
He said the issue would take quite some time to resolve.
Mr Dann also said the defence would be applying to exclude 15 items of evidence currently proposed by prosecutors against Lynn, including the record of interview "and basically everything that flows thereafter".
Lynn was interviewed by police over four days in November 2021. Details of his full police interview have been suppressed, along with details from a covertly recorded conversation and statement made by him to police in July 2020.
The nine-and-a-half hour interview would take nearly a week to be played in court, Mr Dann said.
He also flagged potential interlocutory appeals against decisions relating to the exclusion of evidence, which would extend the time until a trial could occur.
Prosecutor John Dickie said he was concerned about delay.
"The prosecution is keen to have trial as it is at the moment, but if it's unavoidable it's unavoidable," he said.
Mr Dann said that it was.
Lynn was charged in November 2021 with murdering the campers, whose missing persons case became one of Australia's most high-profile crime stories in March 2020.
It's alleged Lynn, 56, killed the couple on March 20 that year, while they all camped in the remote Wonnangatta area of Victoria's alpine region.
Lynn is in custody and will return to court by video link for a further directions hearing on June 22.
