The New Zealand Defence Force and Ministry of Fisheries swooped on boats from the tuna fishing fleet off Great Barrier Island yesterday.
An Air Force Orion and the HMNZS Manawanui found the 110-boat tuna fleet off the coast of Great Barrier Island and staff began boarding the boats.
Lieutenant Commander Hugh Aitken
said five boats had been inspected.
Only minor offences had been discovered - mostly relating to inaccurate fishing records or by-catch records.
"Most of them have been pretty good but there's an element we think are probably offending," he said.
Lieutenant Commander Aitken said most of the skippers had been co-operative.
Most of the tuna fleet are New Zealand-owned and operated.
Because of the value of the catch, the inspection was "timely", Lieutenant Commander Aitken said.
"It will also help to establish whether offences are taking place and support the Ministry of Fisheries in developing data on how the industry is operated."
Fisheries Officers will continue their investigation as the tuna boats come ashore.
Five Defence Force staff were co-ordinating the operation from shore, together with 15 staff on the Manawanui and seven fisheries officers, who were with the Orion crew, helping to locate the boats.
An inflatable craft was used to board the tuna boats, Lieutenant Commander Aitken said.
