Earlier quoted context omitted.
Possession and sale of stolen goods is not legal, just not a crime unless you are aware it's stolen/likely stolen.
Well by that logic it was stolen by the person who dug it up in Italy. After all, there’s someone walking around Italy today that is the heir to this sculpture. You have to draw the line somewhere.
It could also be from the following countries:
At its zenith, the Roman Empire included these today's countries and territories: most of Europe (England, Wales, Portugal, Spain, France, Italy, Austria, Switzerland, Luxembourg, Belgium, Gibraltar, Romania, Moldova, Ukraine), coastal northern Africa (Libya, Tunisia, Algeria, Morocco, Egypt), the Balkans (Albania, Greece, Hungary, Bosnia, Slovenia, Croatia, Bulgaria, Turkey), the Mediterranean Sea, the Black Sea, Asia Minor, and some parts of Mesopotamia and the Middle East (Syria, Lebanon, Iraq, Jordan, Israel).