Italian divers have stopped the search for 15 people still missing from the Costa Concordia shipwreck on the Tuscan island of Giglio in which a total of 32 people are feared to have died.

"We have definitively stopped the underwater search inside the ship," a spokesman for the fire brigade on the island told AFP, explaining that conditions inside the giant half-submerged liner were becoming too risky.

"The conditions are no longer acceptable," he said.

The civil protection agency, which has been overseeing rescue efforts following the January 13 disaster, said in a statement it had contacted the families of the missing and foreign embassies involved to explain its decision.

It added that rescuers would continue to inspect the above-water part of the liner and use specialist equipment to check for corpses on the sea bed in an 18-square-kilometre (seven-square-mile) area around the wreck.

The search for the missing has had to be suspended several times due to choppy seas and small movements of the wreck, which sparked fears that the massive ship could slip off the rocky shelf it is resting on and sink entirely.

Divers have also described tricky conditions inside the ship, with corridors cluttered with furniture and turbid waters. Dives have been limited to a maximum of 50 minutes, making it difficult to penetrate far into the vessel.

The 114,500-tonne ship ran aground on rocks with more than 4,200 people aboard on January 13. A total of 17 bodies have been recovered -- of which 16 have so far been identified -- and 15 people remain missing.