Different countries have in recent years used a wide range of techniques  to try & secure the return of disputed artefacts. Some of these approaches have had more success than others.
South China Morning Post 
Countries go to greater lengths to get looted treasures back
5 Mar 2009
South China Morning Post
China is not the only nation that wants missing relics back and many countries employ different means to retrieve them, write Tim Johnson and Julie Sell
Cambodia, are barely able to halt the plunder of sites like the ancient Angkor temples complex.
Others, such as Italy, have found success in negotiating directly with museums abroad, winning back more than 100 pieces in the past three years, including the stunning Euphronios krater, an ancient Greek terracotta vase that was held by New York’s Metropolitan Museum of Art and returned early last year.
Rome has made headway in other cases. Late last year, the Cleveland Museum of Art offered to return 14 ancient treasures. And, in 2007, the J. Paul Getty Museum in Los Angeles agreed to return 40 pieces, including frescoes, marbles and bronzes, to Italy after a two-year dispute.
In addition, the museum agreed to adopt new acquisition policies for its collection.
Colin Renfrew, an archaeologist and expert on illicit antiquities at Cambridge University in England, applauded the Getty Museum’s actions and has contrasted its approach to disputed antiquities with those of other museums, including the Metropolitan Museum in New York and the Museum of Fine Arts in Boston. He has criticised both of those museums publicly for not returning disputed antiquities.
Many experts on art and antiquities, however, draw a clear distinction between pieces obtained long ago and more recent pieces going on the market. The British Museum, like many major institutions, adheres to a 1970 Unesco protocol that was intended to thwart the theft of art and artefacts.
Under the protocol, “no respectable museum can respectably acquire an artefact that has come onto the market after 1970”, Professor Renfrew said.
The protocol has led to a number of repatriations. Last year, Syria returned relics to Iraq, France returned items to Burkina Faso and Denmark repatriated relics to China. Both Italy and the Vatican returned parts of the looted Parthenon to Greece.
Last year, in the Ethiopian town of Axum, tens of thousands of jubilant people turned out for the unveiling of a treasured obelisk that was taken by Italian troops in 1937 but returned after lengthy negotiations between Rome and Addis Ababa.
Last month, the Iraq Museum of Antiquities opened its doors for the first time since the world watched in shock as much of the collection vanished in the wake of the 2003 US invasion. Iraqi officials believe most of the valuable artefacts were cleared out by expert thieves who used the chaos as cover.
“The real damage to the museum … was done by professionals,” said Abdul Zahra al-Talqani, a spokesman for the Ministry of Tourism, which pushed for the reopening of the museum.
He said that while more than 9,400 artefacts are still missing, the museum had got back an additional 6,000.
Some of Iraq’s most precious heritage remains abroad, looted in a different era, most notably Babylon’s Ishtar Gate, which sits in Berlin’s Pergamon Museum.
“We have important pieces in London, Paris, Berlin,” Mr Talqani said. “We ask for them to be returned, but do not expect them ever to come home.”