KLANG: Police believe the pirates who attacked the Singapore-owned oil tanker in the Straits of Malacca near Pulau Ketam early Tuesday, may have had "inside help". This was based on several turn of events when the pirates boarded the oil tanker carrying five million litres of diesel, siphoning off part of the cargo and kidnapping three Indonesian crew-members. "We believe the heist was pulled off possibly with "inside help" from certain crew members," said Federal marine police deputy commandant (operations and intelligence) ACP Abdul Rahim Abdullah. He said senior crew members of the ship did not raise the alarm or send out distress signal when the incident occurred at 1am, and when the captain, first officer and chief engineer were taken away. "Our (police) patrol boats were out on their rounds as usual but never received any distress signal from the ship, despite three key crew members being taken with all their belongings, passports and documents. "We are puzzled as to why they did not push the distress button. This is highly suspicious and we have not discounted an inside job behind the robbery," said Abdul Rahim. Furthermore, he added, to siphon diesel oil from the ship required technical skills. Speaking to reporters on board a police patrol boat that took them to the vessel today, he said there were 18 crew members – 10 Thais, seven Indonesians and one Indian national, all aged between 28 and 54, and none were harmed by the eight hijackers who were armed with a pistol and parangs. He said the crew members who were abducted by the pirates were all believed to be Indonesians. No ransom demand has been made. Crew members lost several of their belongings including handphones and US$17,000 in various foreign currencies. According to the crew members, the hijackers who came in a speed boat set upon them about 1am before two other ships, the same size as the Japanese-built oil tanker called Naniwa Maru No.1 arrived and sandwiched their vessel before anchoring and siphoning three million litres of diesel worth RM8.2 million. The hijack took place when the vessel slowed down to about eight knots from its cruising speed of 30 knots and was about 16 nautical miles (30km) off Malaysian shores. The authorities came to know about the hijacking about 10am when they were notified by a Singapore-based shipping agency. Abdul Rahim said the vessel had left Singapore on Monday and was bound for Myanmar to deliver the diesel it was carrying when the pirates struck at the area which is close to Northport.