The Labour Party leader is calling on the Government to release Crown Law's opinion on the liability for cleaning up the Rena oil disaster.
The ship ran aground on Astrolabe Reef off Tauranga on 5 October, spilling up to 350 tonnes of oil and 88 containers into the sea.
Phil Goff says he was angry when he heard that the Mediterranean Shipping Company, which chartered the Rena, was not accepting liability for the clean-up effort.
The company says liability rests with the ship's owner, Costamare Shipping from Greece, and is donating $1 million toward the clean-up.
Prime Minister John Key says the Attorney-General and Crown Law are exploring all legal options to pursue the companies involved for the cost of the clean-up and that will be known in time.
But Mr Goff said on Wednesday the Government needs to release the Crown Law opinion, what the cost of the clean-up will be, who is liable and what action the Government will take to get the money needed for it.
Mr Key has described the Mediterranean Shipping Company's donation as a good start, but if there is a substantial amount of oil released into the sea and the clean-up cost is greater, then the company might want to reconsider its position.