Dubai - In an audio recording released Sunday, a British naval officer can be heard saying the transit of a British-flagged vessel through the Strait of Hormuz must not be impaired under international law as Iranian naval forces warn the vessel to change course.

The audio, released by maritime security risk firm Dryad Global, shows how the British navy was unable to prevent the ship’s seizure by Iranian Revolutionary Guard forces on Friday. The seizure has prompted condemnation from the UK and its European allies as they continue to call for a de-escalation of tensions in the critical waterway.

In the recording, an Iranian officer can be heard telling the Stena Impero to change course, saying: “You obey, you will be safe.”

“Alter your course to 360 degrees immediately, over,” the officer says, before saying the ship is wanted for security reasons.

A British naval officer from the HMS Montrose frigate patrolling the area around the Strait of Hormuz is heard telling the Stena Impero, which had a crew of 23 on board, that its passage must be allowed.

“Sir, I reiterate that as you are conducting transit passage in a recognised international strait, under international law your passage must not be impaired, intruded, obstructed or hampered,” the British officer says.

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.”

Iranian officials say the seizure of the British oil tanker was a response to Britain’s role in impounding an Iranian supertanker two weeks earlier.