Deep sea divers have "unpacked a wall of people" from the hull of a smuggler's trawler on the sea floor near the Italian island of Lampedusa, untangling the dead in the latest and most painstaking phase of a recovery operation following the ship's fiery capsizing.

It was the first time the divers had been able to reach the hull, and authorities said 38 more bodies were recovered on Monday, raising the death toll from last Thursday's tragedy to 232.

Scores more are believed missing. Most were Eritreans trying to reach Europe in search of asylum and a better life.

"They unpacked a wall of people," said Navy Captain Paolo Trucco of the deep sea specialists. The bodies "were so entwined, one with the other, it is indescribable. They were so trapped they were difficult to pull out".

Deep sea divers in their weighted suits and sturdy port-holed helmets were able to spend up to 30 minutes at a time at the site of the wreck 47 metres below the surface - much more than a scuba diver's typical seven to 10 minutes at that depth. This allowed them to remove debris that was still floating around inside narrow passage ways to reach the vessel's hull.

"Mattresses, blankets, stairs. Anything that would float. Imagine if you put a house in a centrifuge and you see what winds up in the air. That is what happened," Trucco said.

Diver Marco Presti said he and his colleagues had to pull each body out by the arms.

"One diver after the other, we passed them from one to the other, and placed them on the stern of the boat," he said.

Coast Guard Captain Filippo Marini estimated it would take two more days to complete the search and recovery mission.

Only 155 of the migrants survived the fiery shipwreck.

Survivors have said there were at least 500 people aboard the 18-metre-long boat when it sank.

More than 300 people are feared drowned in Thursday's disaster, one of the worst single incidents involving economic
migrants and refugees attempting the perilous sea crossing from northern Africa to Europe.

"We found a whole row of bodies that were inside and outside of the wreck," said police diver Riccardo Nobile. "We tried to recover those that we could and we pulled them up in the time that we had remaining, but it was very little time."

Refugee crisis

The disaster comes as European states prepared to address the growing refugee crisis. The recent disaster has underscored the human cost of Europe's immigration crisis and the role that human trafficking gangs play in exploiting vulnerable migrants desperate to reach Europe.

Thousands have died attempting the crossing, and the decades-long problem has been exacerbated this year by thousands of refugees fleeing civil war in Syria.

It has also renewed debate over Italy's tough immigration law, which has put the survivors of the wreck under criminal investigation.

Many of the survivors are currently living in unsanitary conditions in an overcrowded refugee centre, while the bodies are being stored in rows of coffins in a giant airport hangar.

Italian Prime Minister Enrico Letta has asked for more European assistance, but has also blamed lax border controls in Libya, the departure point for many of the boats, including the latest shipwrecked vessel.

European Commission President Jose Manuel Barroso is due to visit on Wednesday to discuss joint action on the crisis.

About 30,000 asylum-seekers have landed in Italy so far this year, more than four times the number from 2012, although still below the 50,000 in 2011 at the height of the Arab Spring revolts.

The majority are Eritrean, Somalis and Syrians.

Source: Agencies