Doctor Fabrice Michel of the La Timone hospital in Marseille, where the child was hospitalized, confirmed to Associated Press on Friday "the child had tested positive in serological tests to SARS-CoV-2," the virus that causes COVID-19.
But he says the child had not developed any symptoms of COVID-19.
The child died of brain damage relating to cardiac arrest with a form of Kawasaki disease. About 125 children in France have developed symptoms similar to those of Kawasaki disease and some French doctors believe it is linked to coronavirus.
Doctors in Britain, Italy and Spain have been warned to look out for this rare inflammatory condition in children.
Last month, Britain's Paediatric Intensive Care Society issued an alert to doctors noting there has been an increase in the number of children with "a multi-system inflammatory state requiring intensive care" across the country.
The group says there was "growing concern" that either a COVID-19 related syndrome was emerging in children or a different, unidentified disease might be responsible. (AP) SCY