Six British former soldiers have been taken into custody in Chennai in India.
The ex-soldiers were arrested on board MV Seaman Guard Ohio.
Girlfriend appeals for help as boyfriend faces Christmas in Indian jail after being arrested for gun crimes
The British former soldiers were aboard the MV Seaman Guard Ohio, within Indian waters, when they were detained on 12 October 2013.
The ship is operated by AdvanFort an American firm specialising in 'security' and 'intelligence operations'.
Reportedly, the 10 crew and 25 'soldiers' 'have not been able to explain why they entered Indian waters or why they do not have the necessary documentation required to carry weapons.'
The crew and 'soldiers' include Britons, Indians, Ukrainians and Estonians.
In June 2013, four Britons sailing a converted warship were arrested off Senegal.
The Senegalese authorities said the four - all ex-UK servicemen - were detained on suspicion of 'illegal activity'.
According to a document from the U.S. District Court of the Eastern District of Virginia, the AdvanFort Company previously pled guilty to 'Aiding and Abetting the Making of a False Statement During the Acquisition of Firearms.'
Armed ship in India had prior brushes with law
Earlier, reports noted that the MV Seaman Guard Ohio was principally operating around Galle in Sri Lanka.