Divers have pulled out a woman's body from the capsized Costa Concordia, raising to 13 the number of dead in the January 13 accident off the Tuscan island of Giglio.
Civil protection official Francesca Maffini told reporters the victim was wearing a life vest and was found in the rear of a submerged portion of a ship by a team of fire department divers.
The unidentified body was being removed from the ship. Before the body was found this afternoon, there were at least 20 people missing.
Earlier, Italian officials said it was possible that unregistered passengers had been aboard when the Concordia struck a reef off Giglio.
Only eight of the 13 bodies so far found have been identified.
"There could have been X persons who we don't know about who were inside, who were clandestine" passengers aboard the ship, Franco Gabrielli, the national civil protection official in charge of the rescue effort, told reporters at a briefing on the island of Giglio, where the ship, with 4,200 people aboard rammed a reef and sliced open its hull before turning over on its side.
Mr Gabrielli said that relatives of a Hungarian woman have told Italian authorities that she had telephoned them from aboard the ship and that they have not heard from her since the accident. He said it was possible that a woman's body pulled from the wreckage by divers yesterday might be that of the unregistered passenger.
But the identity of that body and of three male bodies, all badly decomposed after days in the water, have yet to be established. Mr Gabrielli said they have identified the other eight bodies: four French, an Italian, a Hungarian, a German and a Spanish national.
The search had been halted for several hours earlier, after instrument readings indicated that the Concordia has shifted a bit on its precarious perch on a seabed just outside Giglio's port. A few metres away, the sea bottom drops off suddenly, by some 20-30 metres, and if the Concordia should abruptly roll off its ledge, rescuers could be trapped inside.
Passengers were dining at a gala supper when the Concordia sailed close to Giglio and struck the reef, which is indicated on maritime and even tourist maps.
There are also fears that the Concordia's double-bottom fuel tanks could rupture in case of sudden shifting, spilling 2,200 metric tons (almost 500,000 million gallons) of heavy fuel into the sea around Giglio, which is part of a seven-island archipelago in some of the Mediterranean's most pristine waters and a prized fishing area.
But Mr Gabrielli said pollutants found near the ship have been detergents and other substances, including chlorine, apparently from the wreck of the ship, which carried some 3,200 passengers and a crew of 1,000. Any fuel traces found were "compatible with what you find in a port," he said.
Ferries and cargo ships regularly call at Giglio's port.
Sophisticated oil-removal equipment has been standing by, waiting for the search-and-rescue operations to conclude before workers can start extracting the fuel in the tanks.
The Italian captain, Francesco Schettino, is under house arrest as prosecutors investigate him for suspected manslaughter, causing a shipwreck and abandoning the ship while many were still aboard.
Operator Costa Crociere, a subsidiary of US-based Carnival Cruise Lines, has said that Capt Schettino had deviated without permission from the vessel's route in an apparent manoeuvre to sail close to the island and impress passengers.
Capt Schettino, despite audiotapes of his defying Coast Guard orders to scramble back aboard, has denied he abandoned ship while hundreds of passengers were desperately trying to get off the capsizing vessel. He has said he co-ordinated the rescue from aboard a lifeboat and then from the shore.