Martin Hinton’s former Supreme Court role, which he left last year to serve as DPP, has already caused some public commentary, with former Attorney-General Chris Sumner arguing he “should not be appearing in any Supreme Court matters – particularly those involving the liberty of the citizen”.

But questions have now been raised in the District Court, with a sentencing submission by the office of the DPP criticised as containing “apprehended bias” because it invoked a previous judgement written by Hinton before he left the bench.

Nahuel Sebastian Lowery has pleaded guilty to possession of 111g of methylamphetamine, with his lawyer Yasmin McMahon, of McMahon and Co, earlier this month seeking a suspended sentence, citing her client’s significant health problems.

She also argued her client had “fully cooperated with the justice system, accepted guilt, expressed remorse” and had “good prospects for rehabilitation”.

But prosecutor Samuel Adams is seeking a prison term, citing the precedent of Edward Dale Armistead, who was found guilty and jailed over one count of trafficking methylamphetamine in 2016. An appeal against his conviction and sentence was later dismissed by a Supreme Court bench including then-Justice Hinton, just days before he was announced as the successful applicant for the DPP role.

McMahon, for Lowery, told District Court judge Michael Burnett: “I understand that my friend [the prosecution] wishes to make some submissions with respect to the case of Armistead [however] my friend is obviously appearing on the instructions of the Director – and the Director wrote the judgement on Armistead.”

“The judgement was delivered at a time when I anticipate that the Director was aware that he was going to return to be the Director,” she added.

“I obviously don’t know about exactly when he would have known that, but Armistead was delivered I think about 10 days before [the appointment] was finally announced.”

McMahon argued that “the ordinary person in the street, in my submission, would apprehend that there is some bias in the court relying on this decision as it places the prosecution in an advantageous position”.

“I think it’s this particular case that is problematic… in my submission, it’s not applicable to the case before your Honour.”

That is nonsense… the law is the law, and it doesn’t matter which judge wrote it

But Adams responded: “In relation to the claims that there is apprehended bias… that is nonsense, and there’s no basis for that submission.”

“The law is the law – and it doesn’t matter which judge wrote it.”

Adams said the Armistead case was relevant “as it provides that a home detention order must not be made if it may impact the public confidence in the administration of justice”.

“This offending is not at the lower end of the range of objective seriousness, due to the weight of the methylamphetamine possessed by the accused, the evidence the trafficking was not isolated and the sophisticated manufacturing set-up,” he said, arguing the Armistead case was “simply the most recent and relevant authority on this point”.

McMahon argued Lowery was “not charged with manufacture for sale”, and that his “psychological make-up and drug addiction at the time led him to be interested in how drugs were manufactured and made”.

“That’s the basis for the manufacture – not in order to produce significant amount of the drug to sell,” she said.

She argued the prosecution should “refer to earlier cases and other cases… then I think that might be the appropriate way to address the issue”.

“I think it’s a difficulty with this particular case given who wrote this case,” she said.

But Adams told the Judge that “the Director is opposed to the notion that your Honour can’t use Armistead when sentencing the accused” as “it is the relevant authority”.

McMahon responded: “That creates a real problem for the court, and what the court is to do in circumstances where the Director has written the judgement, and then the Director relies on that judgement as part of sentencing – particularly to oppose suspension or home detention of a sentence to be imposed.”

“And I don’t have an answer for your Honour about how your Honour is to deal with that, but that’s the difficulty,” she said.

“In my submission, for the ordinary person in the state it creates a real apprehension of bias that your Honour is being asked to apply a case which the Director has written.”

InDaily sought comment from Hinton, whose office referred to previous responses he has made, in which he insisted he had “no greater advantage as to the approach of particular Supreme Court judges to their task than does astute counsel who study the judgments of the Court”.

“I am confident that the court will approach matters in which I am involved in a strictly impartial manner in keeping with established principle,” he said previously.

He declined to comment further “as this matter is currently subject to adjudication by the District Court, and could be subject to appeal”.

Lowery is to be sentenced later this month, after detailed sentencing submissions were received in writing.