The case of a sex-offending school bus driver shows the Ministry of Education should look at how it responds to similar cases, the school's lawyer says.
Robert Burrett, 64, will be sentenced next month for sexually abusing girls aged between five and 12.
He had been a teacher and principal at several schools, before working in Christchurch as a caretaker and then a contracted bus driver for children with special needs.
Burrett pleaded guilty in February to charges including indecent assault, sexual violation including rape, and possession of objectionable publications.
Lawyer Grant Cameron said there was an urgent need for the Ministry of Education, the Privacy Commissioner, the Children's Commissioner and others to develop a response when red flags were raised about potential offenders.
"It has to be of major priority, this was terrible offending. It's probably one of the worst cases in New Zealand history," he said.
Mr Cameron said the Ministry of Education needed to develop a new protocol to respond to allegations of sexual offending against children with disabilities who could not speak for themselves.
The ministry had the primary responsibility for the children but left it up to Burrett's employer to deal with the situation, he said.
"The outcome here of shifting that person to another route might have been entirely satisfactory to the driver and the contractor but it's totally inadequate in terms of protecting the children."
A ministry spokesperson said it would be insisting that CCTV cameras be installed in buses to monitor drivers, but Mr Cameron said a holistic approach was needed.