The issue of access to the communications technology required for a remand on electronic bail or a sentence of home detention arose in the Kaitaia District Court again last week.
And again Judge Greg Davis expressed his concern at the inherent unfairness faced by many Far North residents.
Electronic monitoring requires Spark cellphone reception, which Corrections told the court was not available in much of the North.
The monitoring authority demanded that the link be provided via Spark, although its employees also used Vodafone, which was much more widely available.
One defendant who appeared last week, and was a candidate for home detention, claimed that a strong Spark signal had been found at his house, but the monitoring officer who assessed the address only went as far as the letterbox, where there was no signal.
He was remanded on bail so further inquiries could be made to find a suitable address, but Judge Davis was not impressed that people's liberty was effectively being determined by Spark's cellphone network.
"I am deeply concerned that people living in rural areas are often denied the opportunity to serve an electronically-monitored sentence, or to be remanded on e-bail, because the equipment needed isn't available.
"Often the only other option is to send these people to prison, when they would not be jailed if they lived where there was a cellphone signal, and that isn't fair.
"Too many people who are eminently suitable for electronic monitoring don't have that option, and have to go to prison."
The limiting of sentencing options was having a disproportionate effect on Maori, he added.
A Corrections officer told the court the monitoring officers who inspected an address before e-bail was granted or an electronically-monitored sentence was imposed carried Vodafone cellphones but were not allowed to use that network for monitoring purposes.
Only Spark was acceptable, and people were going to prison as a result.
The Corrections Department said some of what was presented in court was not correct.
In a statement, a spokesman said:
"Cell phone coverage is required for an address to be deemed suitable for electronic monitoring.
"The safety of field officers is paramount so they must be able to make a call from their mobile phone from the address.
"All Field Officers carry both Vodafone and Spark cell phones so they have access to both of these networks.
"As a background, in February 2015 Corrections signed a contract with 3M to provide electronic monitoring (EM) bracelets.
"As 3M provides GPS and radio frequency technology Corrections was then able to offer home detention in areas previously considered to be unsuitable.
"The EM service is carried over the Vodafone network.
"Corrections works within the limitations of New Zealand's telecommunications capability.
"If an offender proposes an address where there is no cell phone coverage it will be deemed as unsuitable.
"It is important that First Security staff are able to contact emergency services if they feel they are in a threatening situation.
"A small number of areas across New Zealand have limited or no, cell phone coverage.
"Even in areas with cell phone coverage, each property must be assessed for technical suitability as environmental factors on the property can affect the operation of the equipment."