Malaysian police have arrested a man accused of being the mastermind behind the botched hijacking of an oil tanker in the piracy-prone Malacca Strait last week, reports said Wednesday.

The 42-year-old was arrested late Monday in the capital Kuala Lumpur, the official Bernama news agency said, without specifying his nationality.

Police said he was suspected of planning to sell the tanker's load of diesel to a buyer in a neighbouring country.

Ten Indonesian pirates boarded the Malaysian tanker off Langkawi island on June 14 but their planned attack was foiled when a quick-thinking sailor raced off in their speedboat, stranding them on the vessel.

Vulnerable

He returned with five police patrol boats and after a tense standoff, the pirates were persuaded to surrender.

The Malacca Strait is one of the world's most important waterways, with 50,000 ships carrying about one-third of the globe's trade passing through it each year.

However the strait, 960 kilometres (600 miles) long and 1.2 kilometres wide at its narrowest point, is notoriously vulnerable to pirate attacks.

Governments in the region also believe it is tempting for terrorists.