In the meantime, Britain continues plans to deploy a Europe-led "maritime protection mission" to safeguard shipping in the area after Iran's Revolutionary Guard seized the Stena Impero in the Strait of Hormuz on Friday.
The audio shows that a British frigate was too far away from the targeted tanker to keep it from being diverted into an Iranian port despite U.K. efforts to keep it from being boarded.
The British navy said Thursday it had stopped three Iranian paramilitary vessels from disrupting the passage of a British oil tanker through the Strait of Hormuz.
Gone, at least for now, are the halcyon days when strong military and political ties between Britain and the United States meant that Washington could assume it had a staunch partner for standing up to a foreign foe.