An army specialist team parachuted onto the island of Tristan da Cunha, Britain's most remote overseas territory, a defence ministry statement said.

One of three British nationals diagnosed with suspected hantavirus linked to the outbreak on the MV Hondius cruise ship is on the island.

The team of six paratroopers and two military clinicians, all from the 16 Air Assault Brigade, descended from a Royal Air Force (RAF) A400M transport aircraft "in a daring parachute drop", the statement said.

Vital oxygen supplies and other medical aid were air-dropped almost simultaneously.

The urgent response came after confirmation by the UK Health Security Agency (UKHSA) on Friday of a suspected infection in a British national on the island.

Tristan da Cunha, a group of volcanic islands with a population of around 220 has no airstrip and is accessible only by boat.

With oxygen supplies at critically low levels, officials said an airdrop was the only viable option to deliver care in time and support the island's two-person medical team.

Foreign Secretary Yvette Cooper paid tribute to the armed forces for an "extraordinary operation".

The drop involved a long-range flight of nearly 6,800 kilometres (4,200 miles) from RAF Brize Norton in central England to Ascension Island, followed by a further 3,000-kilometre flight to Tristan da Cunha, the statement said.

Armed Forces Minister Al Carns said the operation had been carried out in "incredibly challenging circumstances"... with the utmost professionalism and composure under pressure".

The two other British nationals involved in the hantavirus cruise ship outbreak were earlier evacuated to the Netherlands and South Africa.