The World Health Organization

Several experts have called for the Games to be postponed or moved over fears it could speed up the spread of the virus around the world.

The WHO has rejected these calls, however, claiming it would "not significantly alter" the outbreak.

They have now called an emergency meeting for later this month to re-evaluate the situation.

"The emergency Committee meeting will consider the situation in Brazil, including the question of the Olympics," said Nyka Alexander, a spokeswoman for the WHO.

More than 4,800 people have died in Liberia since the outbreak began in West Africa in late 2013. The country celebrated what it thought was the end of Ebola in May, but then six more cases emerged the following month.

That started the clock over — 42 days or two incubation periods of 21 days — before Liberia could return to being free of transmission. On Thursday, officials announced they had made it without any more cases.