The boatie who dumped hundreds of litres of oil in the Viaduct Harbour could face an $800 fine and a bill for the clean up that could cost thousands of dollars.
A team from the Auckland Harbourmaster's office used a skimmer to clean the water of oil today.
Around 180 litres were dumped into the Harbour.
Harbourmaster John Lee-Richards said the team removed about 1000 litres of oil and sea water using the skimmer.
He said he has no doubt that someone intentionally dumped the oil in the middle of the night.
"There was so much of it, it wasn't an accident. Somebody's got some oil in their bilge and thought: Bugger this, I'm not paying for septic tank [company] to come and pump this out, I'll wait until midnight," Mr Lee-Richards said.
He said the costs included running two boats at $250 an hour, six staff and paying a company to dispose of the oily water.
The clean-up operation finished this afternoon, Mr Lee-Richards said.
"You could drink the [Viaduct] water, if you were brave," he said.
He said the team was alerted to the engine oil spill about 1am. The spill was between 50 and 80 metres long and 15 metres wide.
The viaduct basin is home to a number of large luxury boats and Mr Lee-Richards said because of the size of the spill, there was a good chance it came from one of them.
He said no one had owned up to the spill but he "might do some further investigations down a few lines".
