Italy's highest court has upheld a 16-year jail sentence for the captain of the capsized Costa Concordia luxury liner for his role in the 2012 shipwreck, which killed 32 people.

Francesco Schettino, 56, was originally found guilty in 2015 of manslaughter, causing a shipwreck and abandoning his passengers.

Friday's ruling exhausted his appeals process, with the court rejecting his claim that others bore the blame for the disaster.

Free pending the decision, Schettino is expected to start his prison sentence in the coming hours.

READ MORE: Costa Concordia audio transcript

Schettino was commanding the vessel, which was carrying more than 4,200 passengers and crew, on January 13, 2012, when it hit rocks off the Tuscan holiday island of Giglio, tearing a hole in its side and eventually forcing it to keel over.

Investigators severely criticised his handling of the disaster, accusing him of bringing the 290-metre-long vessel too close to shore.

Schettino had also been accused of delaying evacuation and losing control of the operation during which he abandoned ship before all the 4,200 passengers and crew had been rescued.

The captain's lawyers had insisted the accident and its deadly consequences were primarily due to organisational failings for which the ship's owner, Costa Crociere, its Indonesian helmsman and the Italian coastguard should have shared the blame.

They also argued that it was not the collision, but rather the chaos that ensued owing to the ship losing power that was the direct cause of the deaths.

Schettino could not be blamed for the mechanical failures, they said. Costa Crociere avoided potential criminal charges by accepting partial responsibility and agreeing to pay a one million euro ($1.2m) fine.

Five of its employees received non-custodial sentences after concluding plea bargains early in the investigation.