During a ceremony at the culture ministry in Bern, Swiss Interior Minister Elisabeth Baume-Schneider handed over a partial statue and two Mesopotamian reliefs to Iraqi Foreign Minister Fuad Hussein.

The three works, which are 1,700 to 2,800 years old, are "of great significance" to Iraq, the ministry said in a statement.

They were confiscated during a criminal procedure in the Geneva canton last year, it said.

The main person accused in that case was handed a prison sentence for document forgery and for violating the Cultural Property Transfer Act, which bans the transfer of stolen or looted cultural goods, the ministry said.

An additional 43 cultural items had been confiscated by Swiss authorities in the case, it added.

The three objects returned Friday were discovered and documented during official excavations in Iraq in 1846/47, 1959 and 1976. They all originated in Mesopotamia, today's Iraq.

"They were subsequently removed from Iraq at an unknown date and possibly illegally," the ministry said.

They include two large Assyrian reliefs from the 8th century BC that were found at the major archaeological site Nimrud-Kalhu.

There was also the fragment of a royal bust, wearing a pleated tunic and a royal mantle adorned with pendants, from the ancient city of Hatra in the second to third centuries AD.

Cultural items from Mesopotamia, known as the cradle of civilisation, are among the most endangered categories of Iraqi cultural goods, the Swiss culture ministry said.

They are particularly affected by illegal excavations, smuggling and illegal trading, leading UNESCO to add three sites in Iraq to its list of World Heritage in Danger, including the Hatra site.

Switzerland and Iraq are parties to a UNESCO convention aimed at protecting cultural heritage by banning and preventing illegal imports, exports and transfers of cultural property.

Friday's restitution was the fifth from Switzerland to Iraq since 2005 and "by far the most significant", the ministry said.

While the objects were officially returned to Iraq on Friday, the ministry said they would remain in Switzerland for now to feature in an exceptional exhibit at the ministry through June 7.