The search for survivors on the Costa Concordia cruise ship has been deferred after sensors revealed the grounded vessel had shifted a few centimeters.

Fire department spokesman Luca Cari said in an official statement that instruments indicated the ship had moved from the rocks where it is lodged now.

"We are in the process of evaluating if it has found a new resting point to allow us to resume. For the moment we cannot even go near it," Cari added.

The Italian coast guard hopes to begin salvage work soon, which will include pumping oil off the 114,500t cruiser, but they fear the vessel might slip into 70m deep water off Italy’s west coast.

A specialist team from SMIT, a Dutch salvage company, is set to start drilling through the ship towards the 17 tanks which hold more than 240,000t of fuel.

This operation could take several weeks but experts suggest there is only a small risk of a major fuel leak.

Meanwhile, Italian national newspaper Corriere della Sera reported that federal prosecutors believe the ship was manoeuvring at 15 knots when it hit the rocks on Friday night, just off the Tuscan coast.

Captain Francesco Schettino was placed under house arrest last night at his home near Naples, after investigators held him on suspicion of manslaughter and abandoning ship.

Eleven people are confirmed dead, while 24 are still missing, and rescuers are planning to bore three more holes in the hull in their search for missing passengers.

The vessel, operated by Costa Cruises and built in Italy, was reportedly the largest and most luxurious vessel from the family of Costa Cruises, with a length of 290m and a beam of 36m, and has been in service since 2006.

Caption: Dutch salvage company SMIT will start drilling towards the ship’s tanks to pump off 240,000t of fuel. Image courtesy of Roberto Vongher.