A teenage boy was allegedly groomed for sex by his social worker with drugs and pornography.
The 34-year-old woman was arrested by police this week on charges connected to alleged sexual offending with the 15-year-old boy.
The Oranga Tamariki staff member has been charged with meeting someone younger than 16 following sexual grooming, sexual conduct with a person under 16, exposing a young person to indecent material, as well as two charges of supplying cannabis to someone under 18.
She has been granted interim name suppression until her next appearance in the district court later this month.
Detective Senior Sergeant Megan Goldie was unable to comment further as the matter was before the courts.
The social worker was suspended when the Ministry for Children Oranga Tamariki was told about the allegations, deputy chief executive Alison McDonald said.
"We are appalled at the allegations, which are shocking and deeply upsetting," McDonald said in a statement.
"We are working with the young person and their family to do all we can to make sure they get the support they need."
McDonald said Oranga Tamariki would continue to work with police as they investigated the allegations. It would also conduct an internal review.
"We are undertaking our own response, which includes a review, and an assessment of other children they were working with to ensure their safety."