The Chief High Court judge says Ministry of Justice staff should have picked up on the naming of two sex abuse victims in a court ruling posted online.
The names of such victims are automatically suppressed but they appeared in a sentencing decision on an official courts website earlier in February.
Justice Minister Simon Power has described the breach as totally unacceptable and plans to review what went wrong.
Mr Power says the judge sent the decision to officials with no suppression orders on it and marked to publish.
But Chief High Court judge Justice Winkelmann says suppression rules apply to everyone and do not depend on a judge's direction.
She says the Ministry of Justice has a responsibility, as the publisher, to ensure that all suppressed details are removed from judgments being made public.