Iran has made clear that the seizure of two Greek suezmaxes last month was in retaliation for Greece detaining an Iranian oil cargo on a Russian-controlled ship.

The country’s Supreme Leader, Ayatollah Ali Khamenei, said Iranian forces took over the vessels at the end of May in helicopter-launched raids in the Persian Gulf.

Iran’s action against the two Greece-flag tankers was widely believed to have been made in reprisal against Greek authorities after they allowed the transfer to the US of an Iranian oil cargo that was on board the 115,400-dwt aframax Lana (built 2003).

The Lana, previously known as Pegas, had been seized by Greek authorities in April because it was said to be in violation of sanctions against Moscow. The ship became stuck in Greek waters after an engine failure.

Khamenei was speaking on the anniversary of the death of the founder of the Islamic Republic, Ayatollah Ruhollah Khomeini.

He said: “They steal Iranian oil off the Greek coast, then our brave men who don’t fear death respond and seized the enemy’s oil tanker. But they use their media empire and extensive propaganda to accuse Iran of piracy.

“Who is the pirate? You stole our oil, we took it back from you. Taking back a stolen property is not called stealing.”

Delta Tankers’ 157,400-dwt Delta Poseidon (built 2011) and Polembros Shipping’s 150,000-dwt Prudent Warrior (built 2017) are the two Greek vessels in question.

Their detention was initially said to be due to unspecified maritime violations.

A similar retaliatory incident took place in mid-2019 when Iran seized the UK-flag, 49,700-dwt Stena Impero (built 2018) after the 300,600-dwt Iranian tanker Adrian Darya 1 (built 1997) was captured by the UK on suspicion of attempting to deliver oil to sanctions-hit Syria.