Two British people are self-isolating at home in the UK after potential exposure to hantavirus on the cruise ship struck by an outbreak, the UK Health Security Agency (UKHSA) has said.

They were on the MV Hondius that departed from Argentina a month ago but left the vessel earlier in its journey and do not have symptoms.

The Britons left the cruise ship at St Helena, where it docked on 22-24 April, and flew back to the UK via Johannesburg. The pair contacted health officials when they heard of the cases on the ship.

The UKHSA said their contacts on the journey home are being traced, adding the risk to the general public remains very low.

Prof Robin May, the chief scientific officer at the UKHSA, called the contract tracing work a "very intense effort".

He told BBC Breakfast that it has been "quite a mammoth effort" and "we will continue to do that... for some time".

Three passengers have died on the MV Hondius following the hantavirus outbreak. Spanish authorities have given permission for the ship to dock in the Canary Islands, despite concerns from local officials.

About 150 people are still aboard the cruise ship under "strict precautionary measures", Oceanwide Expeditions has said.

They include 19 passengers and four crew members listed as British, according to figures released by Oceanwide Expeditions on Tuesday.

Three people were evacuated from the ship on Wednesday to the Netherlands for treatment, the operator said - two in a serious condition, and one in a stable condition.

The three evacuees were British, Dutch and German. Oceanwide Expeditions said the German evacuee was "closely associated" with a German woman who died on board the ship on 2 May.

Among them was a 56-year-old British man, who was is in a "stable condition". Spain's health minister earlier said he was the ship's doctor but it is understood that was not correct.

May said on Thursday that the Briton is "in the Netherlands, our understanding is he is doing well".

"He is going to be under investigation for some time. I'm very pleased he's now in hospital and receiving the treatment he needs," May said.

The man has been identified as Martin Anstee, a retired police officer, by several media outlets.

His wife Nicola told the Daily Telegraph it had been "a very dramatic few days".

She told the paper: "He's relieved to be off the ship. He had it quite mild then it got a bit more serious and now he's stable again.

"The fear with this virus is it can deteriorate very quickly so it's been a bit up and down for him. I don't believe he's in imminent danger now but it was horrible."

The US Department of State said it is in "direct contact" with affected passengers and the risk to the American public is "extremely low" at this time, according to the Centers for Disease Control and Prevention (CDC).

Eight people, including a Swiss citizen, are suspected to have contracted the virus, said the World Health Organization (WHO).

The UKHSA said the Britons on the ship would be flown home on a charter flight, probably from the Canary Islands as long as they did not have symptoms.

They would then have to self-isolate or be put into quarantine potentially for up to six weeks, depending on the timing of their last potential exposure to the virus.

May said on Wednesday: "We're going to ask everybody who's exposed to self-isolate but we'll be working very closely to support them on that with regular testing and all the support you'd expect us to put in place.

"That's obviously for their protection well as everybody around them."

May said officials were making efforts to trace people who were in "close proximity" on the flights home taken by the two individuals currently self-isolating in the UK.

"We'll be approaching all of those individuals and again working closely with them to make sure there's no risk to them or to the people around them."

The World Health Organization (WHO) says the risk to the wider public is low and the virus rarely spreads through human to human transmission and only after close contact.

It is still unknown where the outbreak originated from and if people other than cruise ship passengers have been infected with the disease.

The three people with symptoms - who also include a 41-year-old Dutch crew member and a 65-year-old German - were evacuated from the vessel to receive medical help in the Netherlands, the WHO said.

Earlier, the Foreign Office has said it is "working urgently" to get British nationals stuck on board the MV Hondius home safely.

In a statement, Foreign Secretary Yvette Cooper said the situation was "very serious and deeply stressful for those affected and their families".

The Foreign Office said the UK response to the outbreak was being led by the UKHSA working with the WHO.

The aim is to make sure British nationals on the MV Hondius can "all get safely home with proper protection for public health", Cooper said.

Consular staff are in direct contact with British nationals onboard the ship and the Foreign Office has been "working with other countries to facilitate the medical evacuations, to support our Overseas Territories and to get British nationals home safely as quickly as possible", Cooper added.

The UKHSA is also working with governments in St Helena, Tristan de Cunha and Ascension Island on isolation, contact-tracing efforts and response protocols.

The vessel will sail to the Canary Islands where all passengers will be evacuated at the Granadilla port in Tenerife, Spain's health minister Monica Garcia said on Wednesday.

Spanish passengers will be quarantined in Madrid, while those from other countries will be repatriated if they have no symptoms, Garcia said.

Hantavirus is a group of viruses carried by rodents such as mice and rats, and symptoms can include fever, extreme fatigue, muscle aches, stomach pain, nausea and vomiting.

Following the outbreak on the cruise, the UKHSA said the risk to the UK population was "very low" and there was "no need for concern among the general public".