A senior lecturer in criminal law at Waikato University, Matiu Dickson, is critical of marae-based rangatahi courts that give judges the same status as kaumatua.
The Kooti Rangatahi (youth court) initiative began in Gisborne three years ago.
There are now nine of the courts, which are distinctive in giving offenders the chance to have a family group conference in a setting where Maori protocol applies.
Mr Dickson says however that the judges are doing the kaumatua's job and thus taking away the last bastion of Maori ownership of the process.
On a marae, he says, all decisions are made by people who are affiliated to the marae, but the final decision rests with the kaumatua who hold the mana of the pa.
Mr Dickson says the marae community should have the right to decide how low-risk young offenders are dealt with.
Minister sees no problem
Rejecting the criticism, Courts Minister Georgina Te Heuheu says the way the rangatahi court operates doesn't seem to be an issue for those who've agreed to have a court sitting on their marae.
Mrs Te Heuheu says it's up to individual marae to decide who they invite to sit in on a hearing.
She says each court may be distinctive to a particular iwi, but the judicial process - which seeks the involvement of the offender's family - is the same.
The minister says the way the court deals with offenders is proving popular, and there's a lot of iwi interest from regions without one.
