Divers recovered another body from the wreck of the Costa Concordia Sunday, as officials expressed fears that unregistered passengers meant they could not say exactly how many were missing. Divers pulled a woman's body from the cruise liner, recovered from deck seven at the stern of the ship, which brought the death toll to 13. But with divers looking for some 20 officially missing, the head of Italy's protection agency, Franco Gabrielli, warned that there may have been people on board who were not registered on crew or passengers lists. Relatives of a Hungarian woman have claimed she telephoned them from the ship but there was no official record that she was ever on board, said Gabrielli. "Passengers may have been invited on board at the last minute by a crew member," the agency's spokeswoman Francesca Maffini said later. But the ship's purser Manrico Giampedroni told ANSA news agency that it was "impossible there were clandestine or unregistered people" on board. "They are registered and photographed on boarding. It's all electronic. The Costa is a serious company," he insisted. Sources have suggested that since the luxury liner hit rocks just two hours after setting sail from Civitavecchia, staff might not have had time to add the names of last-minute passengers to the relevant lists. Families waiting for news of missing loved ones attended a special remembrance mass on Giglio Island Sunday. "This is a moment for hope, trust and faith," Priest Lorenzo Pasquotti, who sheltered passengers in the St Lorenzo church in the hours after the disaster. "Nothing happens for no reason. Those who are suffering can share their burden with God," he said, urging relatives of missing French and Peruvian victims not to give up hope. Nine days after the luxury Costa Concordia crashed into rocks off Giglio Island with 4,229 people from 60 countries on board, fresh reports of the captain's account of the tragedy emerged. Francesco Schettino fiercely denied abandoning ship after the boat hit rocks, in excerpts from a 135-page statement he gave to Italian prosecutors published in the Italian media on Sunday. He had lost his footing and fallen off as the vessel lurched onto its side, he said. "Me, a coward? A vile person that ran away? I had no life-jacket that night, because my life, from that night, was not worth anything," he told prosecutors in excerpts of the statement published by the daily La Repubblica. But he admitted he had made it to the shore aboard a motorised lifeboat which was difficult to steer and which may have run over people as they floundered in the water. "It might even be that some people's heads were hit," he told prosecutors, in La Repubblica reported. Schettino admitted he had sailed near the island to "salute" its residents. He said he had performed the "salute" many times and had done it to give the island publicity. "I've always done it. We're in the business of doing tourist trips, we show off Italy, we salute the island and it gives us publicity," Schettino said. The captain is under house arrest and is being investigated for multiple manslaughter, abandoning ship and causing a shipwreck, after he steered the boat too close to the Tuscan island. The vessel's owner, Costa Crociere, has said the company was warned too late of the scale of the disaster, though Schettino has disputed their account. Costa Crociere are battling to stave off lawsuits expected to cost hundreds of millions of euros (dollars). Around 400 Costa Concordia employees protested in Genoa on Sunday, "to express their pride in the company," a demonstrator told the daily La Stampa. Giglio Island itself meanwhile was inundated with day-trippers flocking to the scene of the vast beached liner. Visitors fresh off the ferry posed for photos in the winter sunshine in front of the wreck. "They come with their young children as a day trip to see the wreck," said the tiny island's head of tourism, Samantha Brizzi. "I think it's extremely bad taste." As hopes dwindled of finding survivors, police said the families of missing people would have to wait for DNA tests to identify some of the bodies after they had spent a week in the water. Eight of the dead have been identified so far: four French nationals, one Italian, one Spaniard, one Hungarian and one German. Contrary to previous reports, the prefecture in nearby Grosseto could not officially confirm reports that a Peruvian waiter was among the dead. A technical committee met Sunday to evaluate the situation at the doomed ship, which holds 2,380 tonnes of fuel oil, which would cause an environmental disaster if it leaked. The decision to begin pumping the oil out of the ship was postponed until Monday at the earliest. It is not yet clear whether the operation to remove the oil could be done while the search for missing people continues. Gabrielli was due to meet the chief prosecutor in charge of the investigation into the crash on Monday to coordinate the operation.