The Minister of Social Development has asked Child, Youth and Family to investigate the death of a baby who suffocated because his mother was too drunk to keep him safe.
Earlier this year, Ngaire Tukiwaho pleaded guilty in the Rotorua High Court to manslaughter for neglecting to keep her two-month-old son safe.
On Wednesday, Justice Lang jailed the 31-year-old for two years and one month.
The court was told that Tukiwaho had been drinking continuously from the morning of 4 January 2011 for about 12 hours before her son, Tahi Elvis Edwards, died.
The mother-of-five fell asleep in a car and the boy suffocated on 5 January after slipping from her shoulder.
Justice Lang said the death was entirely preventable and Tukiwaho had completely failed her son.
The court was told that another son of Tukiwaho's about the same age died from sudden infant death syndrome in 2008.
Social Development Minister Paula Bennett said on Wednesday it is clear there is a history of serious dysfunction in the family's home.
Ms Bennett said Child, Youth and Family previously removed two children from the father.
The minister said there are too many unanswered questions about the family and she has asked the agency's chief executive to investigate their circumstances.
Outside court, Tukiwaho's lawyer Harry Edward said the woman realises that she has a serious alcohol problem and will undertake whatever programmes are available in custody.
Mr Edward said the sentence was fair and merciful.