HMS Montrose has been working in its current role for several months (Picture: Royal Navy).
The commanding officer of Royal Navy frigate HMS Montrose has revealed that the crew "have been probed daily" by the Iranian Revolutionary Guards Corps in the Gulf since the start of July.
The Type 23 frigate and destroyer HMS Duncan have guided almost 90 British merchant ships through the Strait of Hormuz, the only naval route out of the Gulf, during two months of threats from Tehran.
Tensions in the Gulf escalated two months ago, when Iranian tanker Grace 1 (now known as Adrian Darya 1) was seized by Royal Marines.
This was then followed by the seizure of the Stena Impero, a British-flagged oil tanker, by Iranian forces.
HMS Montrose has been working in its current role since the Stena Impero's detainment.
Commander Will King said the deployment had been “intense but also hugely rewarding".
"We have been probed by the Iranians daily – 115 interactions in all," he said.
"The numbers – 38 transits of the strait, 60 British vessels accompanied, over five million tonnes of UK shipping protected – speak for themselves."
Plymouth-based Montrose has been observed by Iranian forces for each of the 38 journeys through the passage.
The Royal Navy is ensuring the safe transportation of oil and natural gas through the 39-kilometre-wide pinch-point.
The Ministry of Defence has confirmed the UK is actively considering bolstering its surveillance capabilities in the region by deploying Reaper drones.
The UK’s most senior naval officer in the Gulf, Deputy Commander of the Combined Maritime Force, Commodore Dean Bassett, said: "What we’re seeing as partners join is increasing ships and increasing aircraft... that gives us the ability to provide greater degrees of presence.
"It gives a much better opportunity to provide assurance to merchant shipping and also deter illegal activity on the high seas."
Montrose prevented the Iranians from seizing the vessel British Heritage in July, performing a "handbrake turn" at full speed before warding off harassers.
Only warning flares have been fired.
Physical Trainer Damon Bell, who steered HMS Montrose at the time, said: "Protecting the British Heritage was probably the best thing I have ever done."
"We came here, did a real job, made a difference, there’s a meaning to what we’re doing, and you realise that the training works."