The body of an American tourist has reportedly been found on the Greek island of Mathraki, adding to the list of foreigners missing or dead during a record-setting heatwave.

A Dutchman was also found dead on Samos over the weekend, following the recent death of British TV presenter Dr Michael Mosley on the island of Symi.

Another American, Albert Calibet, is among at least three others reported missing.

The US State Department has been approached for comment.

The American found dead on Mathraki was a 55-year-old man, Greek public broadcaster ERT and Athens News Agency reported on Sunday.

The holidaymaker, who has not been named, is said to have last been spotted alive in a bar last week. His body was found on a deserted beach on the small island.

It has been taken to a hospital on the larger nearby island of Corfu for an autopsy.

High temperatures are set to persist in Greece this week. The country is suffering its earliest heatwave on record, with winds from North Africa pushing up the temperature.

Many schools have been forced to close, as have top tourist sites including the ancient Acropolis.

On Saturday, officials reported the death of a 74-year-old Dutch tourist who went missing after going for a solo hike on another island, Samos.

Meanwhile, a search continues for 59-year-old Albert Calibet, a retired police officer from California. He is reported to have disappeared on Amorgos last week after similarly failing to return from a hike.

Greek officials are also searching the island of Sikinos for two French women, aged 73 and 64, according to French news agency AFP.

Earlier this month, officials spent days scouring Symi for Dr Mosley, a prominent British TV doctor who vanished after setting out on a walk from a beach.

His body was found in a rocky area, and investigators concluded that he died of natural causes the day he went missing.