The discovery was made as the officers inspected a Spanish lorry on the A8 motorway on 28 January, officials say.

They spotted the apparent fossils in two parcels and sent them to be examined by a prehistory museum in the nearby city of Menton.

On Friday, an expert revealed the teeth had belonged to reptiles from the Late Cretaceous period – 72 to 66 million years ago – in Morocco, authorities said.

Lorries travelling on the A8 motorway between Spain and Italy are regularly stopped.

Agents open parcels at random as they sometimes contain illegal drugs, customs Samantha Verduron told AFP news agency.

But the latest haul was unexpected.

One of the teeth identified belonged to a Zarafasaura oceanis, a marine reptile measuring about 3m (10ft) and named in Morocco in 2011.

Three belonged to a Mosasaurus, a large aquatic creature that measured up to 12m.

Five other teeth are believed to have been those of a Dyrosaurus phosphaticus, a distant ancestor of crocodiles.

The lorry driver told officers he had been delivering the parcels to people in the Italian cities of Genoa and Milan, French authorities said.

Officials are working to identify the intended recipients of the packages. Collecting fossils is legal, but exporting them often requires a licence.