The captain of grounded cruise liner Costa Concordia said he tripped and fell from the listing vessel and never intended to abandon his passengers as details emerged about the dead and missing.

Victims of the disaster included an Italian man and his five-year-old daughter, a retired American couple treating themselves after putting four children through college and a Hungarian musician who helped crying children into lifejackets, then disappeared while trying to retrieve his beloved violin from his cabin.

The search for the 21 people still unaccounted for ground to a halt after the cruise liner shifted again on its rocky perch off the Tuscan island of Giglio, making it too dangerous for divers to continue. Rough seas were forecast for the next few days.

The bad weather also postponed the start of the weeks-long operation to extract the half-million gallons of fuel on board the vessel, as Italy's environment minister warned parliament of the ecological implications if the ship sinks.

The Costa Concordia was carrying more than 4,200 passengers and crew when it slammed into a reef and capsized on Friday after the captain made an unauthorised diversion from his programmed route and strayed into the perilous waters.

Francesco Schettino, who was jailed after he left the ship before everyone was safely evacuated, was placed under house arrest on Tuesday, facing possible charges of manslaughter, causing a shipwreck and abandoning his ship.

His lawyer, Bruno Leporatti, said Schettino was "a deeply shaken man, not only for the loss of his ship, which for a captain is a grave thing, but above all for what happened and the loss of human life".

The ship's operator, Crociere Costa, has accused Schettino of causing the wreck by making the unapproved detour, and the captain has acknowledged carrying out what he called a "tourist navigation" that brought the ship closer to Giglio.

Costa has said such a navigational "fly by" was done last August after being approved by the company and Giglio port authorities.

However, Lloyd's List Intelligence, a leading maritime publication, said yesterday its tracking of the ship's August route showed it actually took the Concordia slightly closer to Giglio than the course that caused Friday's disaster.

"This is not a black-and-white case," Richard Meade, editor of Lloyd's List, said.

New audio of Schettino's communications with the coastguard during the crisis emerged yesterday, with the captain claiming he ended up in a life raft after he tripped and fell into the water.

"I did not abandon a ship with 100 people on board, the ship suddenly listed and we were thrown into the water," Schettino said, according to a transcript published in the Corriere della Sera paper.

Initial audio of Schettino's conversations made headlines on Tuesday, showing an increasingly exasperated coastguard officer ordering him back on board to direct the evacuation, and the captain resisting, saying it was too dark and the ship was tipping.

Eleven people have been confirmed dead and 21 are missing. Italian officials have only released 27 names, including two Americans, 12 Germans, six Italians, four French, and one person each from Hungary, India and Peru.

The Hungarian victim was identified as 38-year-old Sandor Feher, an entertainer on the stricken cruise ship. His body was found inside the wreck and identified by his mother, who had travelled to the Italian city of Grosseto, according to Hungary's foreign ministry.

Jozsef Balog, a pianist who worked with Mr Feher on the ship, told the Blikk newspaper that Feher was wearing a lifejacket when he decided to return to his cabin to retrieve his violin. Mr Feher was last seen on deck en route to the area where he was supposed to board a lifeboat.

According to Mr Balog, Mr Feher helped put lifejackets on several crying children before returning to his cabin.

Others among the missing include five-year-old Dayana Arlotti, 36, and her father William, who were on the cruise with the father's girlfriend. The girl's parents separated three years ago.

The girl's mother, Susy Albertini, 28, said she last heard from her daughter on Thursday, when she waved goodbye at school.

Mr Arlotti's girlfriend, Michela Marconcelli, who survived, reported seeing Dayana, who was wearing a lifejacket, slide into the water when the boat shifted, but said someone helped retrieve her.

Ms Marconcelli said she was pushed forward on to the life raft, and lost track of her companion and his daughter.

Other missing include retired American couple Jerry and Barbara Heil of White Bear Lake, Minnesota.

Sarah Heil, their daughter, said they had been looking forward to the 16-day cruise after raising four children and sending them all off to college.

"They never had any money," she said. "So when they retired, they went travelling. And this was to be a big deal - a 16-day trip. They were really excited about it."

Passengers have complained about the chaotic evacuation and poor treatment by Costa officials once they got on land, with some saying they were provided only a single night of hotel accommodation and denied help getting to their embassies to get new passports.

Costa owner, Miami-based Carnival Corporation, said it was offering assistance and counselling to passengers and crew and was trying to take stock of lost possessions.

"Costa has also begun the process of refunding all voyage costs including both passenger cruise fares and all costs incurred while on board," Carnival said.

"Our senior management teams are working together to determine additional support."

Rescue operations were suspended early yesterday after instruments attached to the ship detected it had shifted, raising concerns for the safety of rescuers. By evening, officials still did not have enough data to assure the ship had stopped resettling and it was unclear when the search would resume.