A court in the southern port city of Galle issued an order preventing Gotabhaya - the powerful defence secretary under his brother's administration - and three others from leaving the country until the conclusion of investigation.
In January, after the defeat of the President Rajapaksa, a ship carrying 12 container loads of weapons was discovered in Galle.
It is believed that more than 100 firearms were three armouries maintained with permission from the Ministry of Defence.
It was alleged that the Sri Lanka Navy had lost income due to the floating armouries maintained by the company.