The foreign vessel which recently cannibalised the remains of the sunken battleship HMS Prince of Wales and battlecruiser HMS Repulse off the Kuantan coast was also responsible for looting 90 per cent of other World War 2 shipwrecks in the region.
It is learnt that the grab dredger is also wanted by Indonesian authorities for plundering the remains of sunken Dutch warships HNLMS De Ruyter, HNLMS Java and HNLMS Kortenaer in the Java Sea.
The vessel is also notorious for illegally salvaging World War 2 shipwrecks in Singaporean, Cambodian and Vietnamese waters.
A source said the grab dredger was known among the shipping community for its looting activities, which have been ongoing for around 10 years.
"Ten years ago, it resembled a dilapidated barge. But it is now fitted with high-technology equipment.
"They operate mechanically and entirely from the surface of the barge, which is equipped with cranes sporting huge metal claws.
"The claws can plunge more than 200m deep. It chops up the ship and pulls up hundred tonnes of metal in one go."
The source said the vessel would evade detection by turning off its Global Positioning System (GPS), and WiFi devices onboard before going into hiding.
Its crew, said the source, comprised highly-paid Chinese nationals, Nepalese, Bangladeshis and Malaysians.
"World War 2 vessels are usually made of low background steel, copper and brass. These can fetch millions because the metals were made before nuclear testing."
A source familiar with the investigation told the New Straits Times that the China-registered vessel went by a different name when it illegally salvaged Dutch wrecks in Indonesian waters.
"However, it changed its registration when it entered Malaysia in February via Pasir Gudang, Johor.
"The vessel had applied for a salvage permit from the Marine Department. It said it planned to salvage a Chinese ship which sank in Kuantan waters and its application was approved."
The vessel, however, focused its attention on the sunken British warships located nearby.
Having dredged up the remains of the two British warships, the grab dredger then made its way to a private jetty in Tanjung Belung-kor, Johor to offload its loot.
It is understood that the private jetty also features a scrapyard, which stores and melts down metal into bullions.
The source said the activities would have flown under the radar had the scrapyard operator not shared a video on his TikTok account.
"The Malaysian scrapyard operator uploaded a video of the grab dredger transporting a cannon from the vessel to the jetty. The video drew the attention of the authorities."
The man has since deleted his TikTok account and is being sought by the police.
Johor police chief Commissioner Datuk Kamarul Zaman Mahat said officers from the National Heritage Department alerted them last Friday to suspicious activities at Tanjung Belungkor.
A unit from Kota Tinggi was dispatched to the scene to provide security for the National Heritage Department officers.
The suspects, however, had fled the scene by the time authorities arrived.
Kamarul Zaman said National Heritage Department officers found relics and scrap metal believed to be from the HMS Prince of Wales.
Investigators also found 46 unexploded ordnances comprising 135mm and 40mm artillery shells, believed to be from the warship.
Police conducted an on-site controlled explosion of the weapons.
Kamarul Zaman, however, urged the public to steer clear of the Tanjung Belungkor private jetty area as it had yet to be declared free of all ordnances.
Johor Malaysian Maritime Enforcement Agency director First Admiral Nurul Hizam Zakaria said the department was notified by the National Heritage Department on Friday of the grab dredger's activities.
"A patrol team was dispatched to the scene immediately. However, the barge managed to elude enforcement officers and went into hiding."
He said the case had been handed over to the police and the National Heritage Department.