Rena: Worst environmental disaster - Nick Smith

A massive oil spill from the stricken cargo ship off the coast of Tauranga has become New Zealand's worst ever maritime environmental disaster, the Government says.

Environment Minister Nick Smith this afternoon said oil had poured out of a new puncture in the Rena at "fivefold" the rate it had in the days after the ship grounded on Astrolabe Reef.

He said significant amounts of oil would start washing up on beaches around Mt Maunganui from tomorrow and into the coming weeks.

The "tragic" spill was inevitable since the Rena grounded carrying 1700 tonnes of oil at 2:20am last Wednesday, he said.

He promised the Government would hold those who were responsible for the grounding to account.