Diver dies during work on shipwrecked Costa Concordia in Italy

Diver gashes his leg on metal sheet underwater while preparing Costa Concordia for salvage operation

Costa Concordia ran into a rock and capsized off the Italian coast in January 2012, killing 32 people. Photograph: Max Rossi/Reuters

A diver has died working on the Costa Concordia shipwreck, apparently gashing his leg on an underwater metal sheet while preparing the vessel for removal.

The diver – believed to be Spanish – had been working on preparations to fix huge tanks to the Concordia's side to float it off its false seabed and tow it to a port for eventual dismantling, according to a report by Tuscany's La Nazione.

It said he gashed his leg and was then unable to get free, bleeding profusely before a colleague was able to bring him to the surface. The report said he was conscious upon surfacing but later died.

The diver is the first to die during the salvaging of the Concordia, which hit a reef off Giglio island on 13 January 2012 and sank, killing 32 passengers and crew.

The ship was righted in preparation for removal in a 19-hour engineering procedure last autumn in which a system of pulleys wrenched the 300-metre, 115,000-tonne cruise ship from its side to vertical.

A dozen giant tanks were attached to its exposed port side and filled with water to help pull the ship upright.

The project that the diver was working on was to prepare the starboard side, which had been underwater until the ship was righted, to hold a similar number of tanks.

The tanks will be emptied of water and used to float the wreck off the seabed, so it can be towed away from Giglio, brought to a port and taken apart for scrap. Officials say they hope to have it removed by June.

The €600m (£492m) removal project, which is already running at nearly twice its original cost estimates, is the most ambitious attempted for a ship of that size.

In a statement, the head of the civil protection agency, Franco Gabrielli, expressed condolences for the death and recalled the dedication of people working on the wreckage.

He added: "They have workedfor two years without a break, in difficult conditions not without risks, to achieve the common goal of removing the Concordia from Giglio."

The ship's captain, Francesco Schettino, is on trial for manslaughter, causing a shipwreck and leaving the ship before all passengers had been evacuated. Prosecutors have accused him of taking the ship off course in a stunt to bring it closer to Giglio. Schettino has said he saved lives by steering the ship to shallow waters after it ran aground on a reef that was not on his nautical charts.