According to the public broadcaster, a French surveillance aircraft spotted two boats near Ouvea after which a naval vessel intercepted them to escort them to Noumea.
Reports said a Vietnamese fisherman, who was in a serious condition after a suspected diving accident, was immediately taken off and flown by helicopter to hospital.
Two other blue boats were seen near Belep and the navy succeeded in catching one of them.
A week earlier, French surveillance teams helped Solomon Islands catch three blue boats fishing illegally.