The death toll of Italian Costa Concordia wreck rose to 25 on Wednesday after eight bodies were found in the cruise liner that ran aground off the Tuscany western coast on January 13.

According to ANSA news agency, four bodies were found early on Wednesday by divers carrying on search operations in the underwater part of deck four, where lifeboats were stationed, and another four were recovered nearby later in the day.

The body of a five-year-old little girl Dayana Arlotti, who was on holiday with her father, was reportedly among those found on Wednesday.

On the same day, other four ship officials and three employees of Costa Cruises, the company owner of the ship which is part of the world's largest cruise operator Carnival Group, were put under investigation for alleged criminal offences that triggered the tragedy.

Captain Francesco Schettino, 52, was put under house arrest a few days after the accident occurred with charges of manslaughter and abandoning ship, although he has denied any wrongdoing.

Operations of Dutch salvage company SMIT are underway to pump 2,400 tons of fuels from the capsized vessel.