On a fairly regular basis, stories make the news about art on loan to another country that is held hostage there, whether because that country believe that they also have rights of ownership, or by proxy for some other debt. Recently the British Museum was involved in such a case with Aboriginal bark etchings  on loan to Australia.
Britain is now planning on implementing new laws to prevent the same happening when art from abroad is in Britain – preventing any groups in Britain repeating the actions of the Dja Dja Warrung tribe in the above case.
In some instances, fear of such a seizure has prevented artefacts being lent to Britain for exhibitions. Similarly though, British institutions are wary about lending to certain foreign countries, as they feel the risk is too high.
The Times 
March 13, 2006
Art is to be out of reach for ‘cultural kidnappers’
By Jack Malvern, Arts Reporter
WORKS of art lent to British museums and galleries are to be protected by anti-seizure laws to prevent them from being used as hostages in trading disputes.
Russian museums have repeatedly refused to lend art to Britain because they fear that aggrieved businessmen will try to claim the works as collateral for Russia’s debts.
James Purnell, the Minister for Creative Industries and Tourism, has announced plans to give art on loan immunity from “cultural kidnapping”.
The State Hermitage Museum in St Petersburg refused to lend Titian’s Saint Sebastian to the National Gallery in 2003 and has threatened not to co-operate with Tate Modern’s Kandinsky exhibition in June.
The Pushkin State Museum of Fine Arts in Moscow, which also has works by Kandinsky, is nervous about lending its art after 55 of its Impressionist paintings were seized last year on the Swiss-German border because of a trading dispute. Noga, a Swiss company, claims that Russia owes it $900 million (£521 million) after failing to repay a $70 million loan. The seizure of the paintings, which were insured for $1 billion, was overturned by a Swiss court, but museum directors are anxious to avoid a repeat.
Mikhail Piotrovsky, director of the Hermitage, said that he needed “concrete guarantees” that collections would not be impounded. “Art works are now being used as hostages in trading disputes,” he said. “We will reconsider all our agreements for exhibitions with countries which cannot give proper guarantees to art and where governments do not understand that art is not a commercial commodity.”
In 2004 Tate was denied a loan of Constantin Brancusi’s The Kiss from the Craiova Museum of Art in Romania because of fears that an undisclosed party would try to claim it.
Art loans are also vulnerable to claims by countries and ethnic groups which believe that certain artworks should return to their place of origin. The British Museum and Kew Gardens had to fight last year to retrieve a pair of bark etchings, a ceremonial emu and a head-dress when they were impounded in Australia. The Dja Dja Wurrung Native Title Group from central Victoria temporarily prevented the items from returning to Britain.
Mr Purnell has invited the public to contribute to a consultation before preparing legislation.