Italian police have released startling new video showing the interior of the sunken liner Costa Concordia.

The eerie footage shot by police divers shows broken metalwork, staircases, corridors, possessions and furniture.

Its release comes as salvage experts prepare to tow the liner away to be broken up.

The Costa Concordia hit a reef off the island of Giglio in January 2012 and capsized.

Some 32 of the 4,200 people on board were killed and the captain, Francesco Schettino, is on trial on charges including manslaughter.

Last September, engineers righted the 114,500-tonne vessel and have been attaching huge tanks to the sides to float it off the reef.

Once it is ready it will be taken to operator Costa Crociere's home port of Genoa, a five-day trip, to be dismantled for scrap.

Environmental campaign group Greenpeace staged a protest against that decision in its own ship, the Rainbow Warrior.

It argues the work should be done somewhere closer as there could still be hazardous liquids or contaminants inside the wreckage.

"We want all the dismantling...to happen publicly and in the light of day and, above all, choosing the solutions with the fewest environmental risks" said a Greenpeace spokesman.

Further details of the Concordia removal operation, the largest of its kind in maritime history, are expected in the next few days.