A growing fleet of more than 100 “falsely flagged” vessels poses a grave problem to the international system of rules designed to ensure safe and legal shipping, the International Maritime Organization heard on Wednesday.

Fraudulently registered vessels have been linked with ship-to-ship transfers of illegal cargo, the switching off of AIS and the breaking of sanctions, and maritime authorities are often powerless to tackle the problem, a committee was told.

The abuse of the IMO’s regulatory regime has seen ships using faked documents to suggest they are flagged with a bona fide registry or using one of the increasing number of fictitious registries that fail to carry out checks on vessels and their owners.