Tests have ruled out the potentially fatal MERS virus in a Czech man hospitalised in Prague since Tuesday, the Czech health minister said on Wednesday.

"Based on the results of laboratory tests... I can confirm that this was not the MERS disease," minister Svatopluk Nemecek told reporters.

The man born in 1989 was taken to hospital with a cold and fever after having returned from South Korea where the disease has killed 20 people.

The hospital declined to give details about his condition on Wednesday.

On Monday, tests also ruled out the Middle East Respiratory Syndrome virus in a South Korean man being kept in isolation at a hospital in neighbouring Slovakia.

A 65-year-old German man died this month after contracting MERS during a trip to Abu Dhabi, in the first death linked to the virus in Europe this year.

In South Korea 162 people have been infected, 20 of whom have died, after a 68-year-old man contracted the virus on a trip to Saudi Arabia in late May.

Globally, some 1,200 people have been infected with MERS and some 450 have died since the virus first emerged in 2012.

MERS is considered a deadlier cousin of Severe Acute Respiratory Syndrome (SARS), which appeared in 2003 and killed more than 800 people around the world.