The taxpayer's bill for the Rena disaster clean-up will reach about $50 million, a newly-released document from Maritime New Zealand shows.
The Rena ran aground on the Astrolabe reef off Tauranga in October last year, spilling oil and cargo into the sea, in what became New Zealand's worst maritime environmental disaster.
An undated briefing paper, from Transport Minister Gerry Brownlee to cabinet economic growth and infrastructure committee chair Bill English, was released to the Labour Party under the Official Information Act.
Mr Brownlee recommended Mr English approve a $10m funding increase to Maritime New Zealand from the transport budget.
The agency had committed all of the $27m it had available to the Rena clean-up, and estimated it would need an extra $10m to cover the cost of its "significantly reduced" response for the remainder of 2011/12.
The $10m sought was on top of the cost the Crown had already incurred from the disaster, which was approximately $38.9m as of February 21.
"The eventual possible total cost has been estimated at around $50m," the paper says.
Further funding was likely to be needed in the government's 2012/13 and 2013/14 budgets, but was included in the four-year transport budget plan in 2012.
The paper also says the Environment Ministry is working on a separate paper on the long-term environmental recovery plan, which was estimated to cost $3.2m over three years.
Labour's environment spokesman Grant Robertson says the cost shows the government's "folly" of failing to pass legislation that would see the Rena's owners pick up the tab.
A select committee recommended passing such legislation in 2008, and officials advised the National government to complete the legislative work when it took office that year - but it failed to, Mr Robertson says.
Labour MP Phil Goff is now proposing the legislation as a members' bill, but Mr Robertson says the government should introduce its own.
NZN