National  MP Tau Henare has released a heartfelt defence of his jailed nephew, who he claims was duped into using a Maori sovereignty defence against cannabis charges.

Maihi Paraone, the 27-year-old son of Mr Henare's late sister-in-law, was jailed this week for two years and nine months after he, along with his father and uncle, were caught in possession of more than five kilograms of cannabis in Whangarei in April last year.

Another man was jailed for possession of cannabis oil for supply.

According to local media reports, during the trial the four sought leniency after being sentenced to two years of "hapu service" at a local marae last weekend. They had shunned legal representation altogether during the trial on Maori sovereignty grounds.

In a letter to the court, Mr Henare and his wife Ngaire criticised the approach advocated by the group, saying they found out only after Paraone was sentenced that he was facing the charges.

"Had Maihi contacted us right from the beginning we believe the outcome would have been far different," said the letter, released by Mr Henare yesterday.

"We would advise him not to listen to his father when they sacked their lawyers because self-representation based on some fringe political belief system would ensure certain defeat."

Mr Henare's letter said his nephew was only at the address where the drugs were found because of an invitation to watch boxing on television, which should have formed part of his defence during the trial.

Paraone's mother, Yvonne, died of breast cancer five years ago.

Mr Henare's letter claimed Maihi Paraone had helped raise his younger brothers and was looked up to by his cousins. He played rugby, organised sporting and cultural events and almost always had a job.

"We can only assume that a misguided loyalty to a dysfunctional father has got him into this current mess," Henare's letter said, adding that his nephew had a weakness for alcohol, rather than cannabis, as he was entrenched in his rugby club's "binge culture".

Yesterday Mr Henare said he hoped his nephew would use the time in jail to complete studies, but was still angry about how events had unfolded.

"He was led up the garden path" by a "chronically unemployed" father, Mr Henare said.

- © Fairfax NZ News