A guilt-ridden New Yorker has returned a massive marble stone he took from an excavation site in Jerusalem's Old City 12 years ago, Israel's Antiquities Authority said on Tuesday.

The 21-kilo (46-pound) piece of 9th century marble column disappeared from an Israeli Antiquities Authority (IAA) dig in 1997.

Several weeks ago the authority received an email from a priest in New York state who requested forgiveness on behalf of a member of his congregation.

"The fellow confessed to me that 12 years ago he took a stone from Jerusalem and his conscience has bothered him ever since. I wish to return the stone to Israel and hope that you will forgive the man for his transgression," the cleric wrote, according to a statement from the IAA.