They stopped a minibus coming from the Czech Republic last Wednesday as it entered Germany near Regensburg, Bavaria.
The two men and one woman in the bus said they were heading for Frankfurt - and insisted they only had edible things with them.
"We only have sweets and food, they're not illegal are they?" the 36-year-old driver asked the officers when he was stopped.
But when the suspicious officers searched the bus, they found four suitcases stuffed with elephant tusks.
The smugglers are expected to be charged with violating the Federal Nature Conservation Act.