JAKARTA (AFP) - Indonesia's navy said on Thursday that it had found a tanker carrying almost US$400,000 (S$542,000) worth of diesel that was taken by its own crew last week due to a commercial dispute.

"The hunt was conducted day and night, non-stop, by the team," said navy spokesman Edi Sucipto. He said the tanker was found on Wednesday off West Kalimantan province, on the Indonesian part of Borneo island.

The tanker is being escorted to Tanjung Pinang, the provincial capital of Indonesia's Riau Islands, for further investigations, Sucipto said.

The MT Vier Harmoni was initially feared to have been hijacked after setting sail from Malaysia, in waters that have suffered a string of pirate attacks in recent times.

But the Indonesian authorities quickly realised the vessel, which was transporting 900,000 litres of diesel, had been taken by its Indonesian crew due to a dispute.

The navy deployed ships and a helicopter to search for the tanker, which was reported missing on August 16 after setting sail from southern Malaysia a day earlier.

After the tanker disappeared, the Indonesian navy said the captain had contacted the vessel's agent to say the crew were taking it back to Batam island, just south of Singapore, due to an "internal management problem".

The term is commonly used to refer to a dispute between a crew and a ship's owner or charterer.

A scourge for centuries, piracy in South-east Asian had been significantly reduced over the past decade thanks to better regional cooperation and maritime patrols.

But in 2015 the region was struck by a string of hijackings with criminal gangs targeting slow-moving tankers carrying valuable petrol which they would offload and sell.

However in the first six months of 2016, the number of incidents dropped to 24, compared with 54 during the same period in 2015, according to the London-based International Maritime Bureau.

About one-third of global trade flows through the Malacca Strait, which runs between Indonesia, Malaysia, and Singapore.