Six men have been arrested over an alleged plan to use a former Japanese whaling vessel to import more than $60 million worth of cocaine.

The group from Melbourne was monitored for about a year before the boat was intercepted about 1300 kilometres off the coast of Tasmania in December.

The Age newspaper is reporting it was boarded by authorities, despite never entering Australian waters.

Victorian and Federal police arrested the men in Melbourne and Queensland.

Police allegedly found 186 kilograms of cocaine on board when it was intercepted last year.