A container ship which was ordered to anchor off the coast at Vlissingen at the end of December after a hoax bomb alert was carrying over 2,400 kilos of cocaine at the time, officials said at the weekend.

The MSC Lorena, travelling from Senegal to Antwerp, was ordered to dock in Vlissingen after an anonymous caller rang the Belgian authorities, threatening to blow the ship up if it docked in the Belgian port.

The ship spent a week anchored off the Dutch coast while an investigation was carried out and was eventually allowed to continue to Antwerp and unload its cargo.

Several days later, officials found 2,444 kilos of cocaine hidden among a consignment of cocoa from the ship.

Last week Dutch police arrested two Dutch nationals on suspicion of making the calls. One is a 24-year-old man from Delft, the other a 22-year-old man from The Hague.

Police say they expect the bomb hoax was linked to the international drugs trade and that the investigation is continuing. The two men currently face terrorism charges.