French Prime Minister Francois Bayrou on Monday hit out at "alarmist" claims about a significant death toll from Cyclone Chido, which hit the country's Indian Ocean territory of Mayotte.

"I think that it'll be in the dozens and not in the thousands," he told BFMTV. "I think the alarmist and sometimes terrifying figures that have been put forward won't be borne out in reality."

The official death toll from the cyclone that hit the impoverished islands earlier this month is at least 35, with some 2,500 injured.

But a local official of the French territory on December 15 estimated that there were "certainly several hundred" victims, speculating that the death toll could rise to "several thousand".

Since the storm battered the remote archipelago, rumours have circulated about possible mass graves in hard-to-reach areas still inaccessible to rescue teams.

Doubts about the actual toll are linked to the makeshift dwellings where most potential victims lived as well as the Muslim tradition of burying the dead within 24 hours.

Many inhabitants of the flimsy shantytowns that were destroyed in the storm came from the neighbouring Comoros.

French President Emmanuel Macron visited Mayotte last Thursday and said the number of victims would "likely" exceed the first official tolls. (AFP)