The cruise captain who grounded the Costa Concordia off the Tuscan coast did not relay correct information either to the company or crew after the ship hit rocks, the cruise ship owner's CEO said Friday as the search resumed for 21 missing passengers.

CEO Pierluigi Foschi told Italian state TV that the company spoke to the captain at 10:05 p.m., some 20 minutes after the ship ran aground on Jan. 13, but could not offer proper assistance because the captain's description "did not correspond to the truth."

Capt. Francesco Schettino said only that he had "problems" on board but did not mention hitting a reef.

Likewise, Foschi said crew members were not informed of the gravity of the situation.

Passenger video shown on Italian TV indicates crew members telling passengers to go to their cabins as late as 10:25 p.m. The abandon ship alarm sounded just before 11:00 p.m.

"That's because they also did not receive correct information on the gravity of the situation," Foschi said.

The $450 million Costa Concordia was carrying more than 4,200 passengers and crew when it slammed into well-charted rocks off the island of Giglio, Italy, a week ago. Eleven people have been confirmed dead.

The Concordia shifted again on its rocky perch Friday, forcing the suspension of diving search operations for the 21 people still missing and raising concerns about the stability of the ship's resting place. But the search in areas above the waterline resumed in the evening after the ship was deemed stable.

The remarks by Costa CEO Foschi are the latest to indicate a lack of proper communication with authorities on land as the emergency unfolded.

Cruise company at odds with captain

Costa Crociere SpA, which offered support to the captain in the hours after the emergency, has now turned its back on the man who is under investigation for manslaughter, causing a shipwreck and abandoning his ship. Schettino, who was jailed after he left the ship, is under house arrest near Naples.

Costa in recent days has suspended Schettino, announced it is no longer paying his legal fees and has signed on as a civil party in the prosecution, a move that positions it as an injured party and would allow it to seek damages in the case of a guilty verdict.

The cruise ship Costa Concordia lies on its side off the tiny Tuscan island of Giglio, Italy, on Friday. (Gregorio Borgia/Associated Press)

Coast Guard spokesman Cmdr. Cosimo Nicastro said crews will evaluate the ship's stability Saturday morning to see if the diving operation can resume, focusing on an area where passengers would have sought lifeboats, Nicastro said.

It was not clear if the slight movements registered by sensors placed on board the Costa Concordia were just vibrations as the ship settles on the rocks off the Tuscan island of Giglio or if the massive ocean liner is slowly slipping off the reef. Salvage experts suggest it could be because of pockets of air gradually escaping.

The sensors detected that the ship's bow was moving about 15 centimetres an hour and the stern about 7 millimeters an hour, said Nicola Casagli of the University of Florence, who was called in by Italian authorities to monitor the ship's stability.

The Concordia's movements are being watched since any significant shift could be dangerous for divers trying to locate those missing since the Concordia ran aground Jan. 13. An additional fear is that movement could damage tanks holding nearly 2 million litres of fuel oil and lead to leaks.

The sea floor drops off sharply a few metres from where the ship is resting, and Italy's environment minister has warned it risks sinking.

Movements suggest ship isn't stable

On Friday, relatives of some of the 21 missing were at Giglio's port getting briefings from rescue teams.

Casagli told Sky TG24 that some movement in the Concordia was only natural given the immense weight of the steel-hulled ship, which is being held in place by two huge rocks at bow and stern.

But the latest movements indicate it isn't stable, he said. "These are small, regular movements that are being monitored because they're going in the same direction," he told Sky.

Late Thursday, Carnival Corp., the U.S.-based company that owns Costa, announced it was conducting a comprehensive audit of all 10 of its cruise lines to review safety and emergency response procedures in the wake of the Costa disaster. The evacuation was chaotic and the alarm to abandon the ship was sounded after the Concordia had capsized too much to get many life boats down.