A British warship warned an Iranian patrol boat against interfering with the passage of the Stena Impero oil tanker through the Strait of Hormuz, according to a new recording released Sunday, but Iran Revolutionary Guard commandos descending from a helicopter seized it shortly thereafter.
In the audio released by the maritime security risk firm Dryad Global, a British naval officer can be heard telling the tanker that it was operating in international waters and that its "passage must not be impaired, intruded, obstructed or hampered."
The British officer then tells an Iranian patrol boat: "Please confirm that you are not intending to violate international law by unlawfully attempting to board the MV Stena.''
But an Iranian officer told the tanker to change course, saying, "You obey, you will be safe. Alter your course to 360 degrees immediately, over."
The officer said the ship was wanted for security reasons, although Iranian officials say the seizure of the tanker was in response to Britain's impounding two weeks ago of an Iranian supertanker at Gibraltar that was believed to be transporting 2 million barrels of crude oil to Syria. Iran claimed the Stena Impero hit a fishing boat.
Iran continues to hold the tanker and its crew of 23, a mix of 18 Indians, three Russians, a Latvian and a Filipino, but said they are in good health.
Britain has called the seizure of the Stena Impero a "hostile act."
Iranian Foreign Minister Mohammad Javad Zarif blamed John Bolton, U.S. President Donald Trump's national security adviser, for fomenting international tensions with Tehran, saying that only "prudence and foresight" can ease the West's conflict with Iran.
U.S.-Iranian tensions have escalated in the year since Trump withdrew the U.S. from the 2015 international accord aimed at restraining Tehran's nuclear weapons program and reimposed economic sanctions against Iran to curb its international oil trade.
"Having failed to lure @realDonaldTrump into War of the Century, and fearing collapse of his #B_Team, @AmbJohnBolton is turning his venom against the UK in hopes of dragging it into a quagmire," Zarif said on Twitter.
Iran's envoy to London, Hamid Baeidinejad, said Britain needs to contain "those domestic political forces who want to escalate existing tension between Iran and the UK well beyond the issue of ships."
Britain's junior defense minister Tobias Ellwood did not rule out the possibility of imposing economic sanctions against Iran, but said London would be consulting with international allies "to see what can actually be done."
"Our first and most important responsibility is to make sure that we get a solution to the issue to do with the current ship, make sure other British-flagged ships are safe to operate in these waters and then look at the wider picture," Ellwood told Sky News.
Iran's Revolutionary Guards on Saturday released video footage showing speedboats surrounding the Stena Impero before troops in balaclavas descend down a rope from a helicopter onto the vessel.
Iran said the crew members "are in full health, they are on the vessel and the vessel is... anchored in a safe place."
Tehran said, "We are ready to meet their needs. But we have to carry out investigations with regards the vessel. God willing, we will make every effort to gather all the information as soon as possible."