Three vessels whose Indonesian crews were allegedly illegally fishing in Papua New Guinea waters this month remain in quarantine in Port Moresby.
Officials from PNG's National Agriculture Quarantine Inspection Authority are waiting for pest control experts to fumigate the boats.
33 Indonesian fishermen on a total of five boats were arrested earlier this month in Western province for fishing in PNG waters, reportedly for shark fins, without permits.
While two boats and 15 people are in custody in Daru, the remaining 18 fishermen and three vessels were taken to the capital.
Danny Dai from the Quarantine Inspection Authority says upon inspection, the boats appeared to carry cockroaches, spiders and rats.
"We are just trying to fumigate those coackroaches and rats because otherwise those rats may go ashore and we're not quite sure whether they have any diseases or what on the rats. So we're trying to fumigate them and then just get them eradicated before the vessel can go berthside at the wharf."