A ROYAL Navy warship has seized cocaine with an estimated UK street value of £21 million after a 12-hour chase across the Caribbean.

HMS Argyll, which is on counter-narcotic operations in the region, intercepted a suspicious-looking boat after it was spotted by a Maritime Patrol Aircraft.

The Clyde-built Type 23 frigate's onboard Lynx helicopter confirmed the small power boat, known as a "go-fast," was acting in a way typical of drug smugglers, before its sea boats were sent to intercept it.

Once on board, the US Coastguard Law Enforcement Detachment (LEDET) and Royal Navy sailors, who work together on the counter-narcotic operations, discovered bales of cocaine with an estimated UK street value of £21 million wrapped in bin bags.

Five people on board were detained on HMS Argyll and handed over to US authorities on Friday, the Navy said.

The work is part of Operation Martillo, a collaborative effort involving 15 nations, which is aimed at stopping criminal organisations accessing Central America via air and sea, and stopping the illegal movement of drugs from South America to the western world.

Armed Forces Minister Mark Francois said: "The Royal Navy has a hard-earned record of tackling illegal drugs smuggling and we should be extremely proud that HMS Argyll has been involved in a dramatic and very successful operation to disrupt the supply. The operations showed tenacity and professionalism."

HMS Argyll's Commanding Officer, Commander Paul Hammond, added: "My team and I knew that a swift and correct interception was required.

"We worked well with our international partners to give ourselves the best chance of success and I used the exceptional capabilities of a modern warship, including sea boats and the Lynx helicopter, to detain the crew and seize the drugs from the target vessel."

Also on board the Type 23 frigate were Royal Marine Maritime Snipers from Faslane-based 43 Commando Fleet Protection Group.