Salvage work on the Rena reached a milestone on Tuesday with all containers holding hazardous material now removed from the upper decks of the vessel.
Thirty-two containers of dangerous goods, including flammable and toxic chemicals, were on board the Rena when it ran aground on Astrolabe Reef on 5 October last year.
Maritime New Zealand says the containers on the deck of the ship were most at risk of being lost into the sea and it is a relief to have them safely removed.
There are still a number of hazardous containers below deck, but the agency still does not know how many went overboard when the wreck broke in two on 7 January this year.
Meanwhile, four fridges have washed ashore: one on Slipper Island, one on Matakana and two east of Opotiki.
Some 2325 tonnes of waste has now been recovered from the sea and shores since the ship ran aground.