Genetically modified organisms were illegally sent out of the country by University of Auckland staff.
The university yesterday banned the export of all such material without specific approval and warned staff that its reputation could be severely jeopardised.
The Ministry for Primary Industries is investigating the breach, which occurred when lab-grown cells and other biological material were exported without approval.
Yesterday the university said the breaches posed no risk and were a matter of incorrect paperwork.
However, Vice-Chancellor Stuart McCutcheon, in an earlier email to all staff, said the unauthorised exports were an offence under the Biosecurity Act and prosecution could follow.
"These actions have the potential to severely jeopardise the credibility of the university containment facilities and the reputation of the university," he wrote in the email.
Deputy Vice-Chancellor (Research) Professor Jane Harding told the Herald that there were four breaches in the past three years.
Biological material, which was not genetically modified, was incorrectly exported twice.
In two other instances, genetically modified cell lines grown inside a laboratory were sent outside New Zealand to other research facilities.
Dr Harding said the samples were properly contained and there was no risk from the breaches.
When the university became aware of the first breach before Christmas, it notified the ministry and disciplinary notices had been given to the staff involved.
In three of the four instances the materials had been imported before they were sent out of New Zealand.
"None of them were organisms or things that could actually do any damage or be released into the environment ... to give you one example, one of the materials was a shell. They were all strictly contained, the problem is one of not getting the right paperwork."
The university has now introduced interim measures including a ban on the export of such materials in all but exceptional cases.
Dr Harding said more permanent controls were developed.
The breaches occurred at the university's two containment facilities, the Faculty of Medical and Health Sciences Containment Facility and the School of Biological Sciences Containment Facility.