Two British cruise ships carrying a combined 3,300 passengers have been turned away from an Argentina port after visiting the Falklands.
The Adonia and Star Princess arrived off Tierra Del Fuego on Monday, but were not allowed to dock in Ushuaia.
The move could be seen as a snub in a row between Argentina and Britain as the 30th anniversary of the Falklands War approaches.
UK diplomats have been trying to clarify exactly what happened.
A spokesman for the Foreign Office told The Sun: "We are very concerned to hear that the Adonia and Star Princess have been refused access to the port of Ushuaia. We are looking into this urgently.
"There can be no justification for interference in free and legitimate commerce. British diplomats in Argentina are urgently seeking to clarify the circumstances surrounding this incident, and we are in contact with the companies concerned."
According to the paper, the Adonia, operated by P&O Cruises, set off from Southampton on 13 January on the 87-day South America Adventure cruise, with passengers paying up to £30,000 for top notch cabins.
The boat set off for Ushuaia after docking at Port Stanley on Saturday.
The Star Princess, run by Princess Cruises, is on a two-week cruise, which finishes in Chile on 3 March. It was also due to dock at Ushuaia this morning.
But as the vessels approached, the port agents contacted both captains to let them know that local authorities had refused them permission to dock.
Jane Archer, a travel journalist on board the Adonia, told the BBC: "It's simply the fact that we were in the Falklands.
"They said the fact that we've been there means that we can't come in to Ushuaia.
"I've not heard of anything like this before and I don't think anybody had any inkling at all that this was going to happen."
"Everything was planned, we were all going to be going on excursions from Ushaia today. I don't think anybody knew anything was going to go wrong, certainly not the captain as far as I'm aware."
Both vessels headed to Chile instead. There are 2,580 passengers on board the Star Princess, of which 284 are British, while almost all of the 700 passengers on the Adonia are British, and will return to Southampton in April.
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