Talks between Italy and the J. Paul Getty Museum in Los Angeles over 52 art works that Rome says were looted have hit an impasse after the museum said it was prepared to return only half of them, according to Reuters. The Italian Culture Ministry said on Wednesday a letter from the Getty saying the museum would turn over only 26 objects -- not including two prized antiquities whose return Italy had demanded -- had been met with "surprise and disappointment". It did not elaborate, adding simply that the letter was being examined and a statement would be made on Thursday. The negotiations with the Getty are part of efforts by the Italian government to crack down on the trade in treasures excavated illegally and put pressure on museums worldwide to verify the origin of the works that they buy. The campaign has yielded a series of deals between Rome and other U.S. art institutions, such as the Metropolitan Museum of Art in New York and the Boston's Museum of Fine Arts, paving the way for the return of disputed antiquities to Italy. Italian authorities have complained that talks with the Getty, one of the world's richest art institutions, have dragged on with little result and earlier this month Culture Minister Francesco Rutelli said time was up. Rome has particularly insisted on the return of a prized bronze sculpture and a limestone cult statue believed to depict the Greek goddess Aphrodite. The Getty said on Tuesday that the bronze sculpture, known as the "Statue of a Victorious Youth", was found in international waters in 1964 and had been obtained by the museum only after Italian courts declared that there was no evidence that it belonged to Italy. "The Getty believes its ownership of the statue is not subject to reasonable challenge," it said in statement, adding it would not be among the objects it had decided to return. "EQUAL OBLIGATION" As for the Aphrodite cult statue, the Getty said the evidence so far was inconclusive, but it would be prepared to transfer title to Italy if further research lent weight to Rome's allegations that it was looted from its territory. "While I am fully committed to ensuring that the J. Paul Getty Museum fulfils all its international obligations, I have an equal obligation to preserve and protect the Getty Museum's collection," said the museum's director, Michael Brand. "That means I cannot return objects, like the 'Statue of a Victorious Youth', to which Italy has -- by its own admission -- no legal claim, or objects for which there is insufficient or inconclusive evidence to support the Italian claim." Italian ministry officials earlier this month threatened to boycott the Getty, meaning that it would be excluded from Italian cultural exchange programmes and loans of art works, although it was not clear what impact such a measure would have. The Getty case is complicated by the trial in Rome of its former curator Marion True on charges that she conspired with dealers trafficking in stolen Italian antiquities. On Tuesday, a Greek prosecutor also charged True with knowingly buying an ancient artefact which had been illegally dug up and smuggled out of Greece 13 years ago.