ROME (AP) — The captain of the cruise ship that capsized off Tuscany made an unauthorised deviation from its programmed course, a “human error” that led to the vessel’s deadly grounding, the ship’s Italian owner said Monday. Rescue operations, meanwhile, were halted as the wreckage slightly shifted.

The comments from Costa Crociere chairman and CEO Pier Luigi Foschi ramped up the pressure on the captain, who already is under investigation by authorities for suspected manslaughter as well as allegations he abandoned ship before the passengers were safe, violating the Italian navigation code.

Six bodies have been recovered so far from the wreckage of the Costa Concordia, which ran into a reef Friday night and capsised into the port area of Giglio, sparking a frantic evacuation of the 4,200
people onboard.

The rescue operation was called off mid-afternoon Monday after the Costa Concordia shifted a few inches (centimeters) in rough seas. The fear is that if the ship shifts significantly, some 500,000 gallons of fuel may begin to leak into the pristine waters around the island of Giglio.

Fire department spokesman Luca Cari said the ship had shifted a few centimeters vertically and horizontally Monday because of the turbulent waters. He said an underwater search for 16 people still missing was put on hold.

Foschi said his company, which is owned by the world’s largest cruiseline, Carnival Corp., stood by the captain, Francesco Schettino, and would provide him with legal assistance. But he said the company disassociated itself from his behavior.

Costa ships have their routes programmed, and alarms go off when they deviate, the chief executive said in a press conference.

“This route was put in correctly. The fact that it left from this course is due solely to a maneuver by the commander that was unapproved, unauthorised and unknown to Costa,” he said.

Schettino has insisted he didn’t leave the liner early, telling Mediaset television that he had done everything he could to save lives.

“We were the last ones to leave the ship,” he said.

Foschi said the liner had passed all safety and technical tests in its 2011 evaluation. He added that the company’s main concern was the safety and well-being of the passengers and crew, as well as to ensure fuel doesn’t leak out from the upended hull into the water.

The 500,000 gallons of fuel onboard are in 17 separate tanks, Foschi said. Sensors have been put in place to track the movements of
the ship.

Questions have been swirling about why the ship had navigated so close to the dangerous reefs and rocks that jut off Giglio’s eastern coast, amid suspicions the captain may have ventured too close while carrying out a maneuver to entertain tourists on the island.

Residents of Giglio said they had never seen the Costa come so close to the dangerous “Le Scole” reef area.