A Sri Lankan court has barred the once-powerful former defense secretary from leaving the country as police investigate a large weapons cache aboard a ship that operated under his purview.

Police said a court in the southern town of Galle imposed the travel ban Monday on Gotabhaya Rajapaksa, a brother of former President Mahinda Rajapaksa.

Police raided the ship in Galle harbor soon after Mahinda Rajapaksa lost a presidential election in January, and said they found more than 3,000 automatic and semi-automatic weapons on board. They said the weapons were for a private security firm guarding the seas against pirates.

Opposition parties have questioned the legality of the weapons cache.

Gotabhaya played a key role in defeating ethnic Tamil rebels in a civil war during his brother's presidency.