Accident Compensation Corporation chief executive Scott Pickering says he remains committed to bolstering privacy standards at the organisation.
It was revealed last week that an ACC case manager took home a notebook containing the names and bank account details of ACC clients, which was stolen from her house.
Mr Pickering told TVNZ's Q and A programme the incident is being investigated and the staff member is on leave.
He says the investigation is expected to take about a week.
Mr Pickering says staff are committed to improving ACC's record on privacy but he can't guarantee there won't be future incidents.
He says the important thing is that the corporation has made progress in bringing down the number of breaches.
Mr Pickering says a review is underway to ensure the focus at ACC is on its clients.