Queensland authorities say they have identified the ship that allegedly spilled up to 15 tonnes of oil in the Great Barrier Reef a year ago, with charges possible.

Between 10 to 15 tonnes of oil leaked off Cape Upstart in north Queensland in July 2015, before washing up on beaches north of Townsville to Hinchinbrook Island and the Palm Island group.

Ports Minister Mark Bailey said the ship was foreign-registered and the evidence had been forwarded to the Commonwealth Director of Public Prosecutions.

It will be up to the Commonwealth to decide whether the ship's operators will be prosecuted.

He described the case as "absolutely outrageous environmental vandalism". "It does appear to be a hit-and-run by a ship on the Queensland coastline near the reef. We want to bring it to justice and that's exactly what we're doing," Mr Bailey said. "We have been relentless in pursuing them because clearly polluting our coastal waters and our reef is absolutely unacceptable and we've left no stone unturned to identify them and pursue them," Mr Bailey said.

Spill could attract fine of almost $30m

The Government will also seek to recoup the clean-up costs of almost $1.5 million.

A major clean-up of the region's beaches took two weeks, two sea birds died and a turtle had to be rehabilitated for six weeks.

Investigators from Maritime Safety Queensland, Great Barrier Reef Marine Park Authority and Australian Maritime Safety Authority has spent the past 12 months trying to identify the ship.

Initially it was narrowed down to 17 ships which had been in the spill area within 72 hours of when it happened.

"The challenge was then to track down the individual ships, many of which were on international voyages, check on-board records, interview crews and take oil samples for elimination testing against samples from the spill," Mr Bailey said.

Maximum fines for a corporation for a discharge offence can include $11.78 million under Queensland law and $17 million under Commonwealth law.

Source: abc.net.au