Controversial French virologist Didier Raoult has unveiled a study he said showed that an antimalarial and antibiotic treatment of more than 1,000 coronavirus patients successfully removed the virus in 10 days in almost 92 per cent of cases.

Prof Raoult presented the findings of the study, which have not been independently verified, to President Emmanuel Macron who paid a surprise visit to his institute in Marseille, southern France.

The iconoclastic virologist was initially criticised for insisting that a combination of hydroxychloroquine and azithromicyne (HCQ-AZ) all but kills off the virus within just over a week.

He has been administering the treatment to hundreds who have turned up to his IHU Méditerranée Infection institute in the southern port city testing positive for the virus.

French health authorities say doctors in hospitals can choose to use it on seriously ill patients but have baulked at advising doctors to prescribe it for people with milder symptoms.

Prof Raoult initially published a study on just 26 patients - too few for the international scientific community to find them conclusive. Donald Trump, however, has thrown his weight behind the treatment.

Prof Raoult has now presented the results of a far wider study on 1,061 patients to the French president.