An oil tanker operated by BP is reportedly sheltering inside the Persian Gulf amid fears it could be seized by Iran.

A vessel named British Heritage was heading for Iraq’s Basrah terminal before making an “abrupt” u-turn and returning to the safety of the Saudi Arabian coastline on 6 July, according to Bloomberg.

The website reported the British energy giant is worried about retaliation by Tehran after the Royal Marines seized an Iranian oil tanker entering the Mediterranean off the coast of Gibraltar last week.

BP declined to comment, but The Independent understands the company’s ship did change course at the weekend and satellite tracking services confirm it is now sheltering off the coast of Saudi Arabia.

“It’s a psychological game that’s being played,” Olivier Jakob, managing director of consultancy Petromatrix GmbH, said. “Nobody wants to be that one whose vessel is seized in a ‘tit-for-tat’.”

Tensions high as Trump approves new Iran sanctions: In pictures Show all 17 1 /17 Tensions high as Trump approves new Iran sanctions: In pictures Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, their surface-to-air missile is seen as it shoots down a US surveillance drone EPA Tensions high as Trump approves new Iran sanctions: In pictures This photo shows US RQ-4A Global Hawk unmanned surveillance drone. A drone of this model was shot down by Iran on Thursday 21 June AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures An oil tanker is on fire after it was subject to a suspected attacked at the Gulf of Oman on June 13. The US has blamed Iran for the attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures US President Trump holds up a signed executive order to increase sanctions on Iran on 24 June AP Tensions high as Trump approves new Iran sanctions: In pictures Iranian President Rouhani stated in a televised address that the White House is "afflicted by mental retardation" following the increase in sanctions on 25 June EPA Tensions high as Trump approves new Iran sanctions: In pictures An Iranian navy boat tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures A screenshot from a video released by the US Department of Defense that the US claims to show Iranian removing an unexploded limpet mine form the hull of the Japan-owned ship that was attacked in the Gulf of Oman on June 13 Getty Tensions high as Trump approves new Iran sanctions: In pictures An item reportedly found on the Japan-owned oil tanker that was attacked on June 13 in the Gulf of Oman AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures A handout photograph from the US Department of Defense shows a composite material that the US claim was left behind on the hull of the Japan-owned oil tanker following the removal of an unexploded limpet mine Getty Tensions high as Trump approves new Iran sanctions: In pictures A view from the cabin of an Iranian navy boat as it tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack EPA Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The picture suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The pictures suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack EPA

It comes as Iran’s foreign minister accused the UK of “piracy” for seizing and detaining the Grace 1 crude oil supertanker on Thursday. Officials at No.10 have said the vessel was bound for Syria in violation of European Union sanctions.

“Iran is neither a member of the EU nor subject to any European oil embargo,” Mohammad Javad Zarif tweeted on Monday.

“Last I checked, EU was against extraterritoriality. UK’s unlawful seizure of a tanker with Iranian oil on behalf of #B_Team is piracy, pure and simple,” the foreign minister added, using the derisory “B team” term Iranian officials use for the Trump administration.

Iranian state TV said Britain’s ambassador to Tehran had been summoned Monday for a third time over the seizure. Hard-liners in Iran have demanded retaliatory measures, with the country’s former Revolutionary Guards commander Mohsen Rezaee last week claiming it was the country’s “duty” to seize a British oil tanker.

On Monday Iran threatened to restart deactivated centrifuges and ramp up enrichment of uranium to 20 per cent as its next potential big move away from a 2015 nuclear agreement that the US abandoned last year.

The threats, made by Tehran’s nuclear agency spokesman, would go far beyond the small steps Iran has taken in the past week to nudge stocks of fissile material just beyond limits set out in the pact.

Behrouz Kamalvandi, spokesman for Iran’s Atomic Energy Organisation, confirmed that Tehran had enriched uranium beyond the deal’s limit of 3.67 per cent purity, passing 4.5 per cent, according to news agency ISNA.

Mr Kamalvandi also said the country’s options within the next 60 days included enriching uranium to 20 per cent purity or beyond, and restarting the IR-2 M centrifuges dismantled under the deal.

“Let me be clear: Iran should not confuse American restraint with a lack of American resolve,” vice president Mike Pence said on Monday, reiterating Washington’s stance on the dispute.

The confrontation has brought the US and Iran close to the brink of conflict, with Donald Trump calling off air strikes against Iranian targets last month only minutes before impact.