The 45.45m-long vessel, which had been anchored about five nautical miles east of Tanjung Piai, was believed to have been stolen by unknown parties following its seizure and the detention of its crew last Friday during a maritime operation.

A source familiar with the incident said the Jakarta-registered tanker, identified as MT Pratama 128, was first reported missing few days ago after a routine check by the MMEA Tanjung Piai’s monitoring team.

“The MMEA’s marine district 6 operations centre in Johor Baru was notified on the vessel’s disappearance at about 3pm and a search operation was immediately mounted by the marine agency’s patrol boats around the waters off Tanjung Piai. Following the incident, a police report was also lodged by an MMEA officer at the Central police station under the Johor Baru South district police on the vessel’s disappearance early this morning,” the source said.

The police report was later forwarded to the Pontian district police headquarters for further action as the area was under their jurisdiction.

An MMEA strike force on a patrol boat detained and arrested eight Indonesian sailors, including the skipper, from MT Pratama 128 at 1.15am during the Ops Satria Selatan/Ops Zuhal maritime operations.

The vessel was impounded for several offences under the Merchant Shipping Ordinance (MSO) 1952 and was then anchored at the location. It is not known if the vessel was carrying any load as investigations were still in progress.

The seamen, aged between 33 and 43, were brought to the MMEA’s southern region headquarters in Johor Baru for processing and detention.

Another source familiar with the incident said the search for MT Pratama 128 was still ongoing and MMEA has deployed its sea and air assets to try and locate the missing vessel.

“The vessel was earlier seized by an MMEA strike force at the same location where it was missing and was supposed to be under the agency’s guard.

“The vessel, which was considered a case seizure and also documented evidence, may have been stolen by parties with vested interest,” said the source.

The second source added that it was unusual for a sea vessel this large to disappear while in the MMEA’s custody.

“MMEA have already initiated contact with the Indonesian maritime authorities via the Western Fleet Quick Response (WFQR) channels and tracing the PT Pratama 128 via its Automatic Identification System (AIS),” said the source.

The AIS is a popular maritime automatic tracking and monitoring system used on ships and by vessel traffic services (VTS). However, the system can be disabled on board to avoid detection.

Separately, Johor police chief Datuk Mohd Khalil Kader Mohd verified that the MMEA reported the disappearance to his agency.

“I can confirm that police received two reports on the matter. One was related to the seizure of the vessel and another was related to the same vessel that was believed to have been stolen ,” he said when contacted.

Checks revealed that the Jakarta-registered MT Pratama 128 is a 550-tonne deadweight tanker that was commissioned in 1977 and originally called Kasuga Maru No.2.

Over the years, the vessel went through two other registered name changes before arriving at its current name. It had been known as MT Senri Jaya I in 2013, and as MT Kencana Jaya I in 2000.

Its latest run-in with the law was when the vessel’s crew was arrested and its owners fined on January 12 by the Indonesian marine and port authorities for illegally transporting 300 tonnes of crude oil in Dumai.