Survivors and relatives of victims of the Costa Concordia shipwreck clamoured for truth at a pre-trial hearing in Italy on Saturday, with some still waiting for identification of the remains of their loved ones, one and a half months after the disaster.

The giant cruise liner capsized off the Tuscan island of Giglio after hitting a rock on 13 Januaty, killing at least 25 people.

Seven people are still unaccounted for, and eight of the bodies found have yet to be identified.

Prosecutors have accused captain Francesco Schettino of causing the accident by bringing the multi-storey Costa Concordia, which was carrying more than 4,200 passengers and crew, too close to the shore.

Eight other officers and executives of the ship's owner, Costa Cruises, are also under investigation.

"We want to know the truth, what happened, and what we are supposed to do now. That's all we are asking," said Hilaire Blemand, a French national whose 25-year-old son Michael was onboard the ship with his girlfriend Mylene Litzler, 23.

Both are still missing. "It's been too long already, it's been six weeks," he said at a theatre in the Tuscan city of Grosseto that has been turned into a makeshift courtroom to accommodate 250 people including victims' relatives, survivors and lawyers for all sides.

Fighting back tears, at his side, Mylene's mother Brigitte Litzler said her anguish had deepened after identification of the bodies was suspended at the request of the lawyer for one of the ship's officers under investigation.

He argued forensic experts from the defence team should be part of the process.

Mr Schettino, who is under arrest in his home in Meta di Sorrento, near Naples, did not turn up for the closed-door hearing.

His lawyer, Bruno Leporatti, said he could have been in danger had he decided to attend.

The captain "is a man who has feelings, who is pained over what happened. He feels pain for the victims," Mr Leporatti told Reuters Television in an interview this week.

His presence at the hearing would have been "unnecessary and perhaps, with this climate that has been created around him, also a little dangerous for him," Mr Leporatti said.

Mr Schettino is accused of a string of charges including multiple manslaughter and abandoning the 114,500-tonne liner before the evacuation of all passengers and crew.