The vessel named "Mahanuwara" was searched on a tip off received Sunday. Police Media Spokesman SSP Ajith Rohana said 12 containers have been found on board the ship.
Meanwhile Navy Media Spokesman Commander Kosala Warnakulasuriya said the vessel belonged to a private security firm.
Investigations too have revealed that a private firm dealing in arms named Avante Guard has acted as an agent of foreign arms suppliers who provided arms for security services assigned to protect ships sailing in the Indian Ocean, a venture which before 2012, was handled by the Sri Lanka Navy.
The firm had hired the ship 'Mahanuwara' belonging to Ceylon Shipping Lines to carry out their deals.
The firm has also said the armoury inside the vessel was maintained for maritime security under permission from the Defence Ministry.
SSP Ajith Rohana said investigations will focus on whether the firm has been legally authorised to carry out the armoury. (KH)