A British survivor of the disaster, which last weekend killed 13 people, called the offer “insulting”.

The ship’s parent company, Carnival, has been ringing passengers asking if they have had sleepless nights or nightmares in an attempt to help, but psychologists said that questioning could trigger post-traumatic stress rather than relieve it.

This weekend, Costa Concordia owners sent passengers letters telling them how to claim for valuables and offering a refund.

The emergency services log showed that the ship’s captain, Francesco Schettino, had left for dry land over four hours before the last passenger was off the ship.

Lawyers plan to sue in Italy and the US, with over 100 passengers joining a class action, which will be lodged in Miami this week demanding between £100,000 and £1 million in compensation.

Rescue workers found another body on the vessel yesterday, bringing the number of confirmed dead to 13.

It has also emerged that unregistered passengers may have been on the cruise liner when it capsized off an Italian island, meaning more people may be missing than previously announced.

At least 19 people are listed as missing after the ship hit rocks near the island of Giglio, but the figure could be higher.

Franco Gabrielli, the national civil protection officer in charge of the rescue mission, said: "There could have been X persons who we don't know about who were inside, who were clandestine."

He said the relatives of a Hungarian woman contacted the Italian authorities when they hadn’t heard from her since she phoned them from aboard the ship.