Nautilus International is calling for nations to investigate maritime incidents even when they do not occur within their area of jurisdiction.
The British union’s plea is linked to the death of two women at sea in 2010 and 2011.
South African cadet Akhona Geveza died after falling overboard from the 6,696-teu Safmarine Kariba (built 2008), which has now been renamed Maersk Detroit, off Croatia five years ago.
And UK citizen Rebecca Coriam disappeared from the 83,000-gt Disney Wonder (built 1999) in 2011.
Mark Dickinson, general secretary of Nautilus, said: “The disappearance of Ms Coriam is just one of a number of crimes at sea which fail to be properly investigated due to the complex nature of jurisdiction in the global maritime industry, which is made worse due to the lack of regulatory control by some ship registers including many Flags of Convenience.”
He added that British police should be required to investigate all serious criminal incidents involving UK citizens at sea.
“In America, the FBI must be informed about any maritime incidents, in any jurisdiction, which involves US citizens, no matter where a ship is registered,” Dickinson added.
Earlier this month, Koji Sekimizu, general secretary of the International Maritime Organization (IMO), addressed a UK parliamentary committee and called for greater collaboration between port nations and flag states.
Commenting on the case of Geveza, Dickinson said: “On the morning of her death, Ms Geveza was due to meet with the ship’s captain following allegations of sexual assault on board.
“She never made it to that meeting and we have never been convinced by the Croatian authorities’ investigation which concluded that Ms Geveza committed suicide.
“The British Police were ready to investigate but they were never asked to do so.
“Despite the incident taking place on a UK-registered ship, and following repeated calls from the union, the UK government claimed it had no jurisdiction to launch a separate investigation.”
