The Italian cruise ship which crashed in January killing 32 people was sailing with its sealed doors open, unapproved maps and faulty instruments, a newspaper reported on Tuesday citing investigators.
Some of the technical apparatus on board the Costa Concordia had been broken since January 9 -- four days before the tragedy off the Italian island of Giglio, Corriere della Sera said, citing leaked documents from the inquiry.
Ship owner Costa Crociere responded to the report saying that the ship's black box "had in fact only issued an error code, which in no way meant that the device was out of service, as is demonstrated by the fact that the data it contained were perfectly in line with engineers' expectations".
"There is no international regulation or convention that prohibits a ship from sailing in a similar situation," it said in a statement.
A court hearing is due on July 21 at which the full results of technical analysis will be revealed. Captain Francesco Schettino and eight others including three executives from Costa Crociere are under investigation.
The giant liner hit rocks off Giglio on the night of January 13 with 4,229 people from dozens of countries on board. Schettino is accused of delaying the evacuation and then abandoning ship before everyone had been rescued.
Emails cited by Corriere della Sera showed the ship had been due in for repairs on its technical instruments after it reached port on January 14.
"The Vdr (Voyage Data Recorder) has broken down for the umpteenth time... The situation is becoming unbearable," Costa Crociere's technical director Pierfrancesco Ferro is quoted as telling a repair firm in an email.
An officer on board questioned by investigators also reportedly said watertight doors were open at the time of the impact as "this was a practice used during the navigation to ease the flow of people who were at work."
Costa Crociere, Europe's biggest cruise operator, said the doors were not open due to electric malfunctioning as asserted by Corriere della Sera.
It also said that the ship had "all the paper and electronic nautical charts needed to complete the voyage planned".
"It is the duty of the master (captain), based on the voyage plan he himself establishes, to verify that the ship is provided with any further nautical charts," it said.
"The ship should have never sailed so close to the coast," the company said.
Also on Tuesday Costa Crociere said it had awarded a contract worth tens of millions of euros (dollars) to Italian shipbuilder Fincantieri to build 30 steel watertight boxes which will be used to right and refloat the ship.
The boxes, with a combined weight of around 11,500 tonnes, will initially be fixed to one side of the hull and slowly filled with water to raise the ship up and then more boxes will be attached to the other side to balance it.
The Costa Concordia is still lying on its side on Giglio and the overall contract for its salvage has been given to Italo-American consortium Titan-Micoperi.