The Ministry of Education suspended the Pitter Patter Education Centre's licence on November 23, following complaints from families and staff, both past and present, that the owner would lock toddlers in rooms as punishment, feed children mouldy food, and smack them.
The ministry notified parents and staff at the centre that its licence suspension has now been revoked, after the owner, Pauline Murphy, agreed to stay away from the site and not have contact with any children.
Education manager Dianne Wilson said in a letter: "With those conditions in place, and having satisfied staff ratio and management requirements, we made the decision that the centre could re-open and that children could attend."
The complaints related solely to Murphy and no other staff members, she said.
"Suspending a licence for an early learning service is not a decision we take lightly. I acknowledge that the suspension has likely impacted your child and your family, particularly at this time of the year.
"Your child's wellbeing, health and safety is my highest priority and I thank you for your patience and understanding," she wrote.
A new manager, Angela Bary, has been nominated by the centre to oversee its day-to-day running.
The ministry has forwarded the complaints to police and the Teaching Council.
The ministry's investigation will continue, with a site visit planned in January.
On Thursday RNZ revealed that more than 17 people had told the ministry about Murphy's behaviour.
The investigation was launched after four Pitter Patter teachers resigned in a month and written complaints were given to the ministry.
In one complaint, a former teacher said she could no longer take it after seeing the way Murphy had been treating children and staff for years.
Others said their mental health suffered and that more than 20 teachers had left in a two-year period.
RNZ's story prompted more parents and teachers to come forward.
Murphy has not responded to RNZ's repeated requests for comment.
The centre under investigation has no connection to the Auckland childcare centre with the same name.