HARTFORD, Conn. — Three smuggled artifacts from Saddam Hussein’s private airport and palace that were recovered by federal investigators in Connecticut are among dozens of items being returned Monday to Iraq.

The door knocker, water urn and soap dish came to the attention of Homeland Security investigators when a source tipped them off that gold-plated artifacts from Iraq were on the market.

“They’re invaluable to the host country,” said Bruce Foucart, the agent in charge for Homeland Security Investigations in New England.

More than 60 artifacts were being returned to Iraq at a ceremony at the Iraqi consulate in Washington, including the head of a limestone statue representing King Sargon II that was recovered in New York in 2008 by agents who broke up a smuggling ring operated by a dealer in Dubai.

In Iraq, the Islamic State group has destroyed a number of shrines and ancient artifacts in order to eliminate what they view as heresy. Lukman Faily, Iraq’s ambassador to the U.S., said Monday’s ceremony sends a message to Islamic State that Iraq and its allies are committed to rebuilding the country and preserving its cultural heritage.

Faily said the return of the looted items is “a national project and we call upon all countries to help us in preserving this heritage which is not only valuable for Iraq but for all mankind.”

The Smithsonian has trained a cadre of Homeland Security Investigations agents in how to research the provenance of cultural artifacts as they investigate smuggling.

The artifacts recovered by the New Haven, Connecticut-based agents were brought to the U.S. by a government contractor who handed them over when confronted by investigators, Foucart said. The investigation began with a tip in April 2012 and Foucart said his agents became involved because Connecticut was a possible destination for the items.

Among the other items recovered by multiyear investigations in New York, Maryland and Texas are an ancient bronze axe and 21 clay reliefs.