Some family members of 23-year-old tour guide Tipene Maangi, who died in the Whakaari White Island eruption, broke down in tears as they gave their impact statements in court.

The two-week sentencing hearing for six parties over health and safety failures in the lead-up to the eruption began at the Environment Court in Auckland on Monday morning.

It follows a criminal trial into the 2019 disaster which killed 22 people and injured 25 others.

Tipene Maangi worked as a guide for White Island Tours at the time of the eruption.

His family told the court their lives have been changed forever, with many still struggling with grief and mental health challenges four years later.

His mother, Paula Maangi, said she had considered taking her own life in times of pain.

Her husband withdrew from family to deal with grief alone, and died in a car accident in less than a year after the loss of their son, she said.

Mangi said her daughter also shut down emotionally and stopped going to school.

The pain "never goes away", she told the court. Her son was a fluent te reo speaker, a great singer, and a generous brother who took his younger siblings to Rainbow's End just two days before he died.

Maangi said she was still in disbelief that people were allowed on the island when it was at alert level two.

Judge Evangelos Thomas said the hearing was an important moment in the history of the island and the history of the tragedy.

Judge Thomas acknowledged four years was far too long to wait for the voices of those affected to be heard.

Judge Evangelos Thomas at the Whakaari sentencing, Auckland, 26 February 2024. Photo: RNZ / Marika Khabazi.

Alongside Whakaari Management which was found guilty, the companies that pleaded guilty and are due to be sentenced are White Island Tours on two charges, the three helicopter companies Volcanic Air, Aerius and Kahu each on two charges, and GNS on one charge.

Judge Thomas earlier said GNS, the crown research institute that monitors volcanoes, would be sentenced separately on Thursday because "the issues relating to GNS are discrete and separate from those relating to other defendants".

-Lucy Xia/RNZ.