Recording from seizure of Stena Impero is attempt to show Iran’s capability in Gulf

This article is more than 1 year old

This article is more than 1 year old

Iran’s Revolutionary Guards have released an audio recording in which one of their officers appears to tell a British warship to back off as a naval patrol seized a UK-flagged oil tanker in the strait of Hormuz on 19 July.

The clip is of a radio exchange in which a guards patrol boat officer tells HMS Montrose to back off while the Iranians seized the Stena Impero vessel passing through the strategic waterway.

The audio clip begins with an officer directly addressing the Montrose using a call sign: “British warship Foxtrot 236, this is Sepah navy patrol boat: you are required not to interfere in this issue.”

A British-accented voice responds: “This is British warship Foxtrot 236: I am in vicinity of an internationally recognised strait with a merchant vessel in my vicinity conducting transit passage.”

The Iranian officer tells the Montrose that the situation could escalate if it tries to intervene: “British warship Foxtrot 236, this is Sepah navy patrol boat: don’t put your life in danger.”

At the time, the frigate was too far away to defend the tanker – 60 minutes away, according to the UK Ministry of Defence (MoD). The royal navy ship had been covering an operating area of 19,000 nautical miles.

The release of the recording is an attempt to demonstrate Iran’s naval capabilities in the region a day after HMS Duncan, a navy destroyer, arrived in the Gulf to support the Montrose in defence of tankers passing through the strait.

Iran seized the Stena Impero after the UK seized the Iranian-owned Grace 1 off Gibraltar earlier this month. The UK said it had acted to halt a vessel believed to be carrying oil to Syria in defiance of EU sanctions.

Last week Iran’s president, Hassan Rouhani, indicated that his country might be willing to contemplate a tanker swap – but the idea was ruled out by Britain’s new foreign secretary, Dominic Raab, in an interview on Monday morning.

Raab said the two seizures were not equivalent. “Grace 1 was intercepted because it was in breach of sanctions and heading with oil for Syria and that was the intelligence,” he said.

“We were absolutely lawful entitled to detain it in the way we did. The Stena Impero was unlawfully detained. This is not about some kind of barter. This is about the international law and the rules of the international legal system being upheld and that is what we will insist on.”

The MoD said it was examining its records to verify whether the recording was accurate, although insiders said that it “sounded legitimate”.

The new British prime minister, Boris Johnson, has yet to make clear whether he favours upholding the faltering Iran nuclear deal, which has been rejected by Donald Trump’s administration.

On Sunday Rouhani published a message of congratulations to Johnson in an apparent effort to cool tensions.

The Iranian leader said he hoped that Johnson’s previous experience of visiting Tehran as UK foreign secretary would “greatly contribute to removing the existing obstacles on the path of development of relations between the two countries”.

Iran insists its seizure of the Stena Impero was legal, saying the tanker refused to switch on its identification system as it passed through the strait. The former UK defence secretary Penny Mordaunt said the tanker was in Omani waters at the time of the seizure.