[1][3] Their primary function was the replenishing of warships of the Yugoslav Navy with weapons, and as such were designated PO (Serbian: Pomoćni oružar - Ammunition Auxiliary).

[1][5][6] On 22 October 2002, Boka Star was seized by Croatian authorities at the port of Rijeka, following a tip-off from American intelligence, on suspicion that the ship was being used for arms smuggling.

The ship's cargo, loaded at Bar, Montenegro, included 14 transport containers of chemical pellets, declared as activated carbon and water filters, which was in fact 208,337 kilograms (459,304 lb) of explosives, consisting of nitrocellulose and nitroglycerin.

[7] The captain and chief officer of Boka Star were acquitted, but Balić was found guilty in absentia of smuggling arms and issuing forged documents, and sentenced to six years in prison.

[8] Following his arrest in Greece and appeal to the Croatian Supreme Court in 2014, he was released from prison and his previous sentence was dismissed as the original judgement was ruled to be invalid.