Iran said Sunday the fate of a British-flagged tanker it is refusing to hand back after seizing it in the Gulf depends on the cooperation of its crew with an investigation.
A senior official also said the entire crew of the Stena Impero oil tanker was in good health.
The vessel was impounded with its 23 crew members aboard at the port of Bandar Abbas after the Islamic Revolutionary Guard Corps seized it in the Strait of Hormuz on Friday.
The Guards on Saturday released video footage showing a ship with the Stena Impero's markings being surrounded by speedboats before troops in balaclavas descend down a rope from a helicopter onto the vessel.
Iran detained the oil tanker on allegations of failing to respond to distress calls and turning off its transponder after hitting a fishing boat.
Its crew is made up of 18 Indians, including the captain, three Russians, a Latvian and a Filipino.
"All of them are in full health, they are on the vessel and the vessel is... anchored in a safe place," said Allah-Morad Afifipoor, director-general of the Hormozgan province port and maritime authority.
"We are ready to meet their needs. But we have to carry out investigations with regards the vessel," he told Press TV.
"The investigation depends on the cooperation by the crew members on the vessel, and also our access to the evidence required for us to look into the matter.
"God willing, we will make every effort to gather all the information as soon as possible," he added.
Britain called the seizure a "dangerous" and summoned Iran's charge d'affaires on Saturday, urging Iran to de-escalate tensions and release the tanker.
Iran opened an investigation on Saturday into the Stena Impero after it allegedly collided with a fishing boat.
The fishermen had issued a distress call after the collision and contacted the port authority when they "didn't receive any response", said Afifipoor, quoted by Fars news agency.
India, Latvia and the Philippines said they had approached Iran to seek the release of their nationals.
The Stena Impero's owner said it was in "international waters" when it was "attacked by unidentified small crafts and a helicopter".
Iran and the United States have been at loggerheads since May 2018 when President Donald Trump unilaterally withdrew the United States from a landmark 2015 deal putting curbs on the Islamic republic's nuclear program in exchange for sanctions relief.
Tensions in the Gulf have escalated since May this year, when the United States boosted its military presence in the region in response to "indications of a credible threat by Iranian regime forces".
The U.S. administration reimposed tough sanctions on Iran, which responded by increasing its enrichment of uranium beyond limits set in the nuclear accord.
Trump called off air strikes against Iran at the last minute in June after the Islamic republic downed a US drone, one of a string of incidents including attacks on tankers in the Gulf.
Germany and France urged Iran to release the seized Stena Impero tanker as the European Union voiced concern.
British Foreign Secretary Jeremy Hunt said the seizure showed "worrying signs Iran may be choosing a dangerous path of illegal and destabilizing behavior".
Hunt called it a "tit-for-tat" situation, as it came hours after a court in Gibraltar said it would extend by 30 days the detention of the Grace 1 Iranian tanker seized by British authorities in the Mediterranean two weeks ago on allegations of breaching UN sanctions against Syria.
London warned its ships to avoid the Strait of Hormuz, a chokepoint for about a third of the world's sea-borne oil.
Trump said Friday's incident "only goes to show what I'm saying about Iran: trouble. Nothing but trouble."
But Iran remained defiant.
Foreign Minister Mohammad Javad Zarif said Iran's actions were taken to "uphold" international maritime rules.
"It is IRAN that guarantees the security of the Persian Gulf & the Strait of Hormuz. UK must cease being an accessory to #EconomicTerrorism of the US," he tweeted.
In a separate development, Iran said one of its tankers held in Saudi Arabia since being forced to seek repairs in the kingdom is returning to the Islamic republic.
The Happiness 1 tanker "has been released following negotiations and is now moving toward Persian Gulf waters," said transport minister Mohammad Eslami, quoted by state news agency IRNA.
The rare docking came despite escalating tensions between staunch enemies Iran and U.S. ally Saudi Arabia.