The Indonesian Navy has retrieved an oil tanker that had been hijacked by pirates off Borneo arresting nine suspects, all Indonesians, who are believed to had intended to steal and sell the ship’s oil.

The 20 crew members and one passenger of the ship, identified as the MV Hai Soon 12, have been rescued and unharmed, Navy spokesman Edi Sucipto is quoted as saying by local media.

The ship is reported to be carrying some 50,000 gallons of oil.

According to Sucipito, the navy sent a patrol ship to pursue the tanker after it disappeared from the Automatic Identification System (AIS) while underway from Singapore to Dumai city. The ship then reappeared elsewhere transmitting a different vessel name, the KM Aiso, arousing suspicion.

The navy managed to locate the ship and board it, thwarting the planned oil theft.

The MV Hai Soon 12 is said to be flagged under the Cook Islands.

Based on the ship’s latest tracking data, the 1993-built tanker is stopped in Surabaya, Indonesia.