A Briton who contracted the deadly Ebola virus in Sierra Leone is being treated at a specialist hospital after being evacuated to the UK.

The volunteer nurse, who is understood to be William Pooley, tested positive after treating patients suffering from the disease at Kenema Government Hospital (KGH) in the south-east of the country.

It is the first confirmed case of a British national contracting Ebola during the outbreak. There is no cure and outbreaks have a fatality rate as high as 90%.

Mr Pooley, who is understood to be in his late 20s or early 30s, was transported to the UK on a specially-equipped C-17 Royal Air Force jet, which landed at RAF Northolt in west London on Sunday evening.

He was then taken to the Royal Free Hospital in Hampstead, north London, which has the UK's only high level isolation unit. His bed will be surrounded by a specially-designed tent with its own controlled ventilation system.

The only people allowed inside are specially-trained medical staff.

Dr Robert Garry, from Tulane University in New Orleans, has worked at KGH for around a decade on a virus research project.

He said he was told by a university colleague that the test results for William were received on Saturday.

Nurse moved to treat Ebola victims

"They worked as hard as they could, as fast as humanly possible to make these arrangements," he said.

"Of course they were wanting to make sure that he got the best care possible. It was kind of a remarkable turnaround, barely over 24 hours (later) he was heading towards that plane."

Mr Pooley was working at a hospice in the capital, Freetown, but moved to Kenema when he found out other workers at the hospital had died from Ebola.

In an interview with a blogger for freetownfashpack.com published earlier this month, he is reported to have said: "It's the easiest situation in the world to make a difference. I'm not particularly experienced or skilled, but I can do the job and I am actually helping."

Dr Garry praised William's decision to help. He said: "It's a very honourable thing. He saw the need. He read about our nurses who were unfortunately dying there and took it on himself to come over and volunteer and learned how to be as safe as he could."

"But when you work hard like that, when you put in so many hours, you're going to make a mistake and unfortunately that seems to have happened in this case. I just hope the best for him, that he can get the best treatment he can get."

The UK Department of Health said he was not "seriously unwell", while health chiefs have insisted that the risk to the public from ebola is "very low".

There have so far been 2,615 confirmed cases and 1,427 deaths in the outbreak in Africa. Ebola is contracted through contact with an infected person's bodily fluids and there is currently no cure or vaccine.

Symptoms of the virus appear as a sudden onset of fever, headache, sore throat, intense weakness and muscle pain.