There has been a 52 percent drop in reports of concern being made to Oranga Tamariki in the Auckland area, under the alert level 3 restrictions.
With schools closed, Ministry for Children expected to see a decrease in notifications about suspected abuse or neglect, as happened during the first nationwide Covid-19 lockdown in March and April.
Oranga Tamariki deputy chief executive Alison McDonald said usually, about a third of the reports of concern made in Auckland are made by people in the education sector, such as teachers.
But over the last two weeks, she said that had dropped to 7 percent.
Oranga Tamariki is working with other agencies in the community to keep an eye on children, McDonald said.
McDonald said they are worried about the toll the second lockdown is taking on the families they work with.
"The last time that we were in this situation, we talked to a lot of children about how it impacted on them - they missed seeing their family, and like all children, missed seeing their friends.
"But children in care missed the contact with their extended family during the lockdown period."
Reports of concern are expected to increase to normal levels once schools reopen at alert level 2.