He said the two fishing vessels were "well known, repeat offenders" in the Southern Ocean.
Records from the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) show the vessels were on a blacklist for "illegal, unreported and unregulated" fishing.
Mr McCully said the vessels had previously been linked to Spanish interests and the Spanish Government had also been alerted.
Interpol had now been asked to put out an alert which would prevent the Songhua and Kunlun from offloading their catch at nearby ports.
Mr McCully said the photographic evidence collected by the navy could be used in potential legal action against the ships' owners.
Punishing illegal activity in the Southern Ocean has proven difficult in the past. Offending ships changed flags or were handed down small fines by their Governments. The New Zealand navy was not permitted to seize the ships.
CCAMLR records showed Kunlun had been on a blacklist since 2004 and had changed ownership several times. Songhua had been on the organisation's radar since 2008.
Pictures released by the New Zealand Defence Force showed the two run-down ships hauling in several large toothfish specimens.
The species is vulnerable to overfishing and is a popular delicacy in Asian and American restaurants. It can fetch about $70 a kilogram.
Ships of shame
• NZ offshore patrol vessel HMNZS Wellington intercepted two vessels, Songhua and Kunlun, for illegal fishing in the Southern Ocean
• The vessels are using gillnets, which are banned in the fishery. They are also on a watchlist for previous breaches of fishery rules
• The main species in the Southern Ocean fishery is Antarctic toothfish, a luxury dish sold in Asian and American restaurants and in high-end markets