The world’s most expensive gold coin has been seized by New York authorities and returned to Greece after it was determined that the 2,000-year-old coin was a smuggled item, U.S. media reported.

The coin is one of only three of its kind and was minted to commemorate the assassination of Julius Caesar. It features the head of Brutus, who stabbed Caesar, on one side, and two daggers on the other.

It had been sold to an anonymous buyer in an auction and is one of many artifacts worth $20 million, some of them 5,000 years old, which were returned together to Greece.