The United States on Tuesday returned to Italy a ceramic water vase from the sixth century BC that had been sold to an Ohio museum in 1982 by art dealers using falsified documents.

In a statement, the US Immigration and Customs Enforcement agency (ICE) said the rare Estruscan black-figure kalpis, valued at $665,000, was handed back to Italian officials following a ceremony at the Toledo Museum of Art.

Investigators from both nations had established that the kalpis, depicting the Greek god Dionysus turning pirates into dolphins, had been smuggled out of Italy following its illegal excavation prior to 1981.

It was sold in 1982 to the Toledo museum by art dealers Gianfranco and Ursula Becchina, who had previously acquired it from Giacomo Medici, a convicted art trafficker.

"The Becchinas misrepresented the true provenance of the vase to the museum by providing falsified documentation," ICE said. Gianfranco Becchina is currently appealing a 2011 conviction for trafficking in antiquities.

Italian ambassador Claudio Bisogniero, in the ICE statement, said: "These returns are a tangible way to restrain international trafficking in works of art. We are very pleased by this result."