If the man, whose name was not released by the authorities, had found the coins in Belgium, he would have had the right to keep them, but the archaeological objects found in France are the property of the state.
Officials were looking for two properties in eastern France, a French customs spokeswoman told CNN.

The transport included pieces of statues. Credit: JEAN-CHRISTOPHE VERHAEGEN / AFP / AFP through Getty Images
In addition to the Roman coins, authorities found more than 13,000 other “exceptional quality” archeological artifacts, according to the press release.
The transport included bracelets and necklaces made in the Bronze and Iron Ages, Roman and Galician coins and a Roman dodecahedron, of which there are only about 100 known examples.
Other objects included pieces of statues, as well as belt buckles from different historical eras.

The seizure is one of the largest recoveries of looted artifacts in French history. Credit: JEAN-CHRISTOPHE VERHAEGEN / AFP / Getty Images
Officials confiscated a total of 27,400 items of “invaluable value” in one of the largest recoveries of looted artifacts in French history, the press release said.
The customs agency has completed its investigation and will send the file to the public prosecutors in the coming days, a spokeswoman for the agency told CNN on Thursday.
French Finance Minister Bruno Le Maire welcomed “exemplary cooperation” between the French and Belgian authorities.
“It allowed the confiscation of an invaluable archaeological treasure. The perpetrator is liable to imprisonment and hundreds of thousands of euros in customs fines,” he said.
“It is a clear message to those who, for the benefit and selfish pleasure of a few, deprive us of our common heritage and erase entire sections of our history.”
French Culture Minister Roselyne Bachelot-Narquin emphasized “the importance of European cooperation in the face of borderless criminal activity”.