Britain's Foreign Office is investigating a report that an Argentine port authority had said it would bar ships registered in the Falkland Islands from docking.
A yacht master reportedly informed authorities that after a brief stop in Ushuaia, on Argentina's southern tip, he was notified by port officials that they would not allow him to return because his vessel was registered in the Falklands.
Argentina continues to claim the Falklands as its own territory and has only just begun to improve ties with Britain, nearly two decades after the two countries went to war in 1982 over the British-ruled south Atlantic islands.