The president of the Criminal Bar Association says there needs to be firm timelines around how long people should wait for trial.
"Fundamentally, we need to get these people to a trial and that requires a systemic input of resources" - Criminal Bar Association President Chris Wilkinson-Smith
Ministry of Justice figures show 44 percent of people currently in prison are awaiting trial and that could soar even further to 48 percent in 2032.
Chris Wilkinson-Smith told Midday Report the Bill of Rights stated people were entitled to a trial without undue delay.
But he said it did not specify how long was acceptable, or what the consequences for lengthy waits would be.
"Overseas, in Canada and England, there are deadlines so if you can't put a person on trial that has real consequences."
In some jurisdictions, the presumption was that exceeding those deadlines amounted to an "excessive delay", he said.
"I think in England it means that the person has to be released on bail, so there's real teeth to not meeting these deadlines."
A delay of a year between arrest and a trial was the sort of "reasonable level" New Zealand should be aiming for in most ordinary cases, Wilkinson-Smith believed, with perhaps a slightly longer timeframe for more complicated cases.
Documents have revealed a $44 million police plan for a "full refresh" to improve investigations, the quality of evidence, how police disclose evidence in courts and to digitise processes.
Dubbed Reframe, one of its three aims over the next three years is to cut back on remand.
But Wilkinson-Smith said he believed something "far more fundamental" would be required to address the remand backlog.
"We see for example, sexual violation cases taking routinely over two years to come to trial, which means if the person accused has been unable to get bail, they're going to be a remand prisoner for at least two years, which is really unsatisfactory for everybody."
The police's plans would play a part in reducing the backlog, he said, and there had been "well-intentioned attempts" to improve the efficiency of the system, but more resources would be required in order to address the lack of judges, lawyers and police working on cases.
"Fundamentally, we need to get these people to a trial and that requires a systemic input of resources so that you've got enough judges, you've got enough court staff, you've got enough prosecutors, defence lawyers, and the police coming in behind that have done their investigations and made sure the proper documents have got to everybody so that you can have a trial."
Guilty pleas being entered
People remanded in custody are pleading guilty to crimes they have not committed just to get out of prison, a justice advocate says.
Cosmo Jeffery from the Howard League for Penal Reform said others were effectively serving jail sentences for charges they might eventually be cleared of.
The numbers on remand were a huge problem, Jeffery said, especially since many people did not end up in prison after being remanded in custody, because they had already effectively served a sentence.
"Often people do more time on remand than they would have got," Jeffery said.
"Sometimes people plead guilty because they know that they're going to get dealt with quicker or they've done enough time and so they get a mark against their name even when they may not have done the crime."
Meanwhile, people remanded on bail faced their own hurdles, he said.
"Getting a job will be really hard, like you're going to front up to an employer and say 'Well, I've got this charge hanging over me, I may get taken out of the community at any time, would you give me a job?'. And it's pretty much the same trying to get accommodation."
The police are trying to improve their investigation and prosecution processes as part of a wider justice sector focus on reducing the numbers remanded in custody.
Some trials have been delayed or even aborted because of evidence not being disclosed on time - a problem that defence lawyer John Munro said had been getting worse.
"There's significant delays in disclosure, that's increased over the years in my view," he said.
"The effect of lack of information or lack of disclosure can sometimes delay early guilty pleas, for example. Or the state dropping their charges or resolving their charges to lesser charges, or a person obtaining bail."
The Howard League wanted to see dedicated remand centres, which were gaining traction overseas, introduced to New Zealand. These would give people an appropriate place to stay and access to rehabilitation, Jeffery said, during what was often a long wait for justice.