Work has begun to remove the two pieces of a grounded Japanese ship that leaked tons of oil into the protected coast off Mauritius and broke apart.

Tug boats will pull the bow – the smaller part of the shipwrecked MV Wakashio – out to sea and allow it to sink, according to environmental experts on the island.

The larger part of the ship will be dragged off the coral reef where it ran aground and towed away, possibly to India for salvage.

“When the ship split in two, there was further leakage of oil, but it appears most of that fuel was on the other side of the coral reef and was in the high seas,” said Sunil Dowarkasing, an environmental consultant and former parliament member in Mauritius.

“With the sea currents, we don’t know if the new leakage will stay outside the lagoon or not.”

Oil barriers were in place and a skimmer ship to scoop up the fuel was nearby.

Mauritius Oil Spill
Volunteers have been working to clean up the oil spill (Gwendoline Defente, EMAE via AP)

The Mauritius government has closed off the coastal area of the eastern part of the island, where thousands of civilian volunteers worked for days to try to minimise damage to the Mahebourg lagoon and protected marine wetlands polluted by the spilled fuel.

Only officials and hired workers are permitted to work in the coastal area and the waters surrounding the grounded ship.

Experts from France, Japan and the United Nations are also involved in the clean-up work.

“Now, we must rely on the government as our only source of information about the situation, so we are only getting one side of the story,” Mr Dowarkasing said.

“We know that the damage to the area is substantial,” he told The Associated Press. “The mangroves are heavily impacted by the fuel. The extent of the damage to the coral reefs will only be known much later, but it is expected to be serious.”

The Wakasio ran aground a coral reef on July 25.

Mauritius Leaking Ship
The MV Wakashio has split (AP Photo/ Kooghen Modeliar-Vyapooree-L’express Maurice)

After being pounded by heavy waves, the vessel cracked and it starting leaking oil on August 6. The damaged ship spilled more than 1,000 tons of its cargo of 4,000 tons of fuel into the waters of the lagoon, one of the island’s most pristine coastal areas.

Most of the remaining 3,000 tons of fuel had been pumped off the ship in the past week as environmental groups warned that the damage to coral reefs could be irreversible.

The Mauritius government is under pressure to explain why immediate action wasn’t taken to empty the ship of its fuel before it began to leak.

Prime Minister Pravind Jugnauth has blamed bad weather for the slow response, while owner Nagashiki Shipping has said “residual” amounts of fuel remained on the ship after pumping.

It is investigating why the ship went off course and has sent experts to help clean up the damage.

The Mauritius government is seeking compensation from the company.