PORT VILA, VANUATU (AFP) - Vanuatu slapped travel restrictions on its most populous island on Monday (April 19) after tests confirmed a body that washed ashore on the largely coronavirus-free Pacific nation was infected with Covid-19.

Government sources said the dead man was a Filipino sailor whose vessel had left the capital Port Vila a day before his body was found washed up near a village about 5km outside the city on April 11.

The man's crewmates and police officers who retrieved the body had all tested negative for the virus, said the sources, who wished to remain anonymous as they were not authorised to discuss the matter.

It was not clear how or where the man died, or how his body ended up in the sea.

The Pacific island nation has recorded only three coronavirus cases, all in arriving travellers, and the National Disaster Management Office said it was taking steps to ensure there was no transmission among the population of 200,000.

It ordered a three-day ban starting Monday on all outward domestic and international travel from Efate, the island where Port Vila and a large part of the population are located.

"The public are strongly advised to remain calm and maintain safe and healthy hygiene practices at all times," it said.