The drug weighed about 51 kg (112.44 lb), making it the biggest single seizure of the drug on French territory.
In a statement, the customs department said customs officers checked two boxes that had been declared to contain food coming from the Cameroon capital of Yaounde en route to Malaysia.
"In the boxes, they found sachets of cereals including several which were unusually heavy. Opening them, methamphetamine crystals were discovered wrapped in aluminium foil," it said. It did not say if any arrests had been made.
Drug networks are increasingly using West and Central Africa as a transit point for drugs from Latin America to Europe, the United States and Asia. They also use the region as production zone for meth because of weak controls on imports of meth ingredients.
The United Nations Office on Drugs and Crime (UNODC) says the highly addictive methamphetamine is increasingly popular in East and Southeast Asia. One kilo of it costs around $1,500 to make in West Africa but sells for around $150,000 in Japan.
In 2015, French customs seized nearly 513 kg of amphetamines including 96.5 kilograms of methamphetamine. ($1 = 0.8924 euros).