A Royal Navy warship has seized £6.5 million of cannabis in the biggest haul in a decade in the Middle East.

The crew of frigate HMS Montrose captured the 6.5 tonnes of hashish after boarding a suspect dhow sailing vessel in the Gulf of Oman.

It is the third seizure since the start of the year by the Bahrain-based ship and the ninth since the start of its extended mission to the region three years ago.

The navy estimates that Montrose has deprived traffickers of £95 million worth of drugs in that time, with this haul being the heaviest seized by allied warships in the Middle East in a decade.

A navy spokesman said: “While the commandos and sailors conducted their thorough search of the suspect vessel, the ship’s Wildcat helicopter provided support and protection throughout.

Lieutenant Joe Martin, the Royal Marines boarding officer, said: “The hashish, also known as cannabis resin, was tallied and tested aboard HMS Montrose, a UK wholesale value of £6.5 million estimated, then the drugs were destroyed.

“I’m really proud of the team; we conducted this boarding efficiently using the experience we’ve gained over the past three months.

“We learn each time we board a vessel, never resting on our laurels and continually honing our edge.”

Commanding officer Commander Claire Thompson said: “Once again, HMS Montrose and her ship’s company have proven their capability in the battle against illegal and illicit activity in the region.”