A convicted murderer has received a $10,000 government payout after he was held too long in solitary confinement at an Auckland prison.

John Vogel has been awarded the payout after the UN Committee Against Torture ruled his rights were breached after he was confined to a cell for 21 days - six days longer than legally allowed.

Vogel was sentenced in 1988 to life in prison for the murder of Mt Roskill man Peter Hoey, 47, the previous year.

He was freed on parole a decade later, but was recalled to Auckland Prison at Paremoremo in January 2000 after further offending.

It was during his prison recall that Vogel pleaded guilty to four drugs charges - one relating to a urine sample that found cannabis in his system, and three for refusing to give further urine samples.

Vogel asked the visiting District Court judge to sentence him to 21 days of confinement so he could deal with his drug habit.

The judge agreed, even though the sentence was longer than the legal limit of 15 days in confinement.

Vogel was confined to his cell for 23 hours a day, with only one hour to shower and exercise, and no access to visitors, a telephone, radio or television.

In the High Court, Vogel gave evidence that his mental health had suffered, describing his confinement as stressful and "maddening".

"I think when I came out I was one or two degrees more mad."

The UN Torture Committee found that the solitary confinement was a disproportionate penalty in John Vogel's vulnerable state, and found a breach of the Torture Convention, i.e. cruel, inhuman or degrading treatment or punishment which do not amount to torture.

The Attorney-General advised a payment of $10,000 would be made to Vogel, and the Government would contribute to his lawyer's costs.

Human rights lawyer Tony Ellis said it was the first case where the Government
had given compensation to anyone following a finding of a breach of an international
human rights treaty.

The Government is still considering an outstanding question of remedies including
compensation after the UN Human Rights Committee in April 2018 found two preventive detainees had been arbitrarily detained for over a decade each.