Footage has emerged allegedly featuring Iran's Islamic Revolutionary Guard Corps' (IRGC) boats chasing away what is thought to be the Royal Navy Type 45 destroyer, HMS Duncan, in the Strait of Hormuz, a strategic waterway linking Middle East crude producers to key world markets.
The low-quality video, whose authenticity has not been verified yet, shows a warship sailing in the distance while several small boats keep following it.
The exact date of the incident is unknown.
It is still unclear whether the warship in the clip is actually HMS Duncan, but the British destroyer did arrive in the Gulf in late July to join frigate HMS Montrose to escort vessels sailing under the British flag through the Strait of Hormuz.
Social media users have questioned the assumption that the vessel in question is HMS Duncan, and suggested, in turn, that it was a UAE Baynunah-class corvette.
The video emerged online amid escalating tensions between the United Kingdom and Iran following the IRGC's seizure of a British-flagged oil tanker, Stena Impero, last month over alleged violations of maritime rules and dangerous manoeuvres in the Strait of Hormuz.
The detention came a few weeks after Gibraltar's authorities seized an Iranian vessel, the Grace-1 oil supertanker, with assistance from UK Royal Marines, over a suspected crude oil delivery to Syria in breach of EU sanctions. Tehran has denied the allegations, and later said that the British tanker's seizure was not a retaliatory move.
In light of these incidents, the UK announced plans to put together a European-led maritime "protection mission" to police the Persian Gulf and the Strait of Hormuz, while simultaneously agreeing to sign up for a similar US initiative against a purported Iranian threat.