Italian rescuers have found five more bodies inside the cruise ship that ran aground after hitting rocks on Friday, raising the confirmed death toll to 11.
The Costa Concordia captain, Francesco Schettino, is to be held under house arrest, his lawyer says. He faces possible manslaughter charges.
A recording of a call between Capt Schettino and a port official shortly after the crash appears to suggest he left the ship before the passengers.
The captain has previously denied this.
In the recording, released by the Corriere della Sera newspaper, a man who identifies himself as Livorno Port Authority chief Gregorio de Falco can be heard repeatedly telling the captain to get back on board the ship to help the stranded passengers.
"Schettino, maybe you saved yourself from the sea, but I'll make you have trouble for sure. Go aboard," says Mr De Falco.
The captain appears to refuse, replying first that there are rescuers already on board, and then that it is dark and difficult to see.
Mr De Falco replies: "Do you want to go home, Schettino? It's dark, so you want to go home?"
During Tuesday's court hearing, the captain said he could not get on board the vessel as it was standing at a 90 degree angle.
The captain's lawyer told reporters that during several hours of questioning in court, his client had maintained his innocence.
"The captain defended his role on the direction of the ship after the collision, which in the captain's opinion saved hundreds if not thousands of lives," said Bruno Leporatti.
Prosecutors, however, said Capt Schettino's testimony had not changed the case against him.
"He confirmed that he was in command of the vessel at the moment of the impact. His version of the events did not change our charges," said Francesco Verusio.
Shortly after daybreak on Tuesday rescue crews blasted several holes in the ship, now lying on its side metres from Giglio island, in order to gain access to areas they had not yet been able to search.
Hours later, the coast guard announced that more bodies had been found.
The BBC's Matthew Price, on Giglio Island, says it is not clear whether the bodies are crew members or passengers, but the coastguard said they were aged between 50 and 60 and were wearing life vests.
The bodies were found near one of the assembly points where people were told to gather in an emergency.
Before the bodies were discovered, Italian officials said there were 29 people still missing from the vessel.
Teams of specialist divers have been helping with the rescue mission.
The ship, carrying 4,200 passengers and crew, had its hull ripped open when it hit rocks late on Friday, just hours after leaving the port of Civitavecchia for a week-long Mediterranean cruise.
Some people were forced to swim for shore as the angle of the ship made launching lifeboats impossible.
Infrared footage taken from a helicopter, also released on Tuesday, shows lines of people climbing ropes down the exposed hull of the vessel to reach rescue boats on the water.
Capt Schettino, 52, has emerged as the central figure in the investigation.
The Costa Concordia's owners, Costa Cruises, have said Capt Schettino hit the rocks because he deliberately steered the ship towards Giglio Island.
Prosecutors have given more detail, saying the captain wanted to make a close pass of Giglio in order to "salute" a crew member's family who lived there.
On Monday, the shipping newspaper Lloyd's List said it had been able to trace the course of the Costa Concordia though information from satellites.
The paper issued a graphic comparing Friday's sailing with an earlier sailing by the vessel, suggesting that Friday's route had deviated far from its usual course.