ROME In a court appearance on Friday, Marion True, the former curator of antiquities at the J. Paul Getty Museum in Los Angeles, defended herself against accusations that she knowingly bought antiquities that had been illegally excavated. "If ever there was an indication of proof of an object coming from a certain place," or an illegal excavation, "we would deaccession it and return the object, regardless of the statute of limitations," Ms. True said. "And we have shown that we would." She listed artifacts that the Getty returned to Italy during her tenure as antiquities curator, from 1986 until 2005. They included a 2,500-year-old kylix, or drinking cup, by the Greek artists Onesimos and Euphronios; a bronze Etruscan tripod; and some 3,500 objects from the archaeological site at Francavilla Marittima in Calabria. In each case that the museum discovered that a piece had been stolen, she said, it gave the object back. Ms. True was speaking in the Rome courtroom where she is on trial with the American antiquities dealer Robert Hecht on charges of conspiracy to traffic in antiquities looted from Italian soil. In Italian legal proceedings, defendants are allowed to make spontaneous comments, and Ms. True's remarks came in response to testimony by Daniela Rizzo, an archaeologist and prosecution witness. Ms. Rizzo said on Friday that Ms. True could have, and should have, done more to prevent the trade in looted antiquities. "Your cooperation has always been very positive," she told Ms. True, who sat with her lawyers. "But you are an archaeologist, a scholar and a great expert, and you had the knowledge to recognize objects that could have come from Etruria." Perhaps "a closer, more direct collaboration with Italian archaeologists would have been more useful than to return objects over time," Ms. Rizzo said. It was the first time that Ms. True has appeared in court to refute the charges against her in a trial that began nearly four years ago. Even as the proceedings have dragged on from hearing to hearing, often with months of delays in between, Italian Culture Ministry officials have negotiated deals with American museums and private collectors, including the Metropolitan Museum of Art in New York; the Museum of Fine Arts, Boston; and the Cleveland Museum of Art, for the return of artifacts said to have been looted. In 2007, after years of legal wrangling, the Getty agreed to turn over 40 objects from its collection, some of which are part of the prosecution's case against Ms. True and Mr. Hecht. The return of the objects had no bearing on the case. The charges against Ms. True surprised many in the art world. During her tenure at the Getty she tightened the museum's policy on collecting antiquities and collaborated with Italian investigators looking into international trafficking in such pieces. Sounding calm and sure of herself, Ms. True said the Getty had always followed proper procedures when buying objects on the international market, contacting Italian culture officials to determine if there were liens on specific artifacts. "I didn't have the right to make informal inquiries" in Italy, she said. The two archaeologists sparred as the defense lawyers began their first day of questioning of Ms. Rizzo, who has been on the stand for about a dozen hearings over the past two years. Citing documents on the purchase of several objects by the Getty, Alberto Sanjust, one of Ms. True's lawyers, suggested that Italian officials might have been remiss in providing proof and that they failed to warn the museum that some artifacts might have been looted or illegally exported. The defense plans an object-by-object rebuttal of the prosecution's case for each of the 35 artifacts that Ms. True approved for acquisition and that the Italians say were looted. "Just as long as the trial doesn't drag on until it's time for me to retire," said the chief judge, Gustavo Barbalinardo, who has announced that he plans to step down in three years.