Experts and lawyers representing survivors of the capsized Costa Concordia cruise ship said Saturday that traces of cocaine were found on a sample of the ship captain's hair.

However, cocaine was not found within the hair, or in his urine, which would have indicated that he had used the drug. The lawyers are demanding a repeat of the tests, claiming the samples from Capt. Francesco Schettino may have been contaminated or mislabeled.

Italian consumer protection group Codacons is representing some survivors of the shipwreck of the cruise liner, which rammed a reef near a Tuscan island the night of Jan. 13. Under Italian law, those attaching civil suits to a criminal case must be informed of, and allowed to monitor, evidence and other developments in the probe.

The results found by a court-appointed expert are "very strange," spokesman Stefano Zerbi told The Associated Press by telephone. The group is raising the possibility that the samples "more than anything else, had been badly preserved and contamination might have resulted," Zerbi said.

Prosecutors are investigating Schettino for alleged manslaughter, causing a shipwreck and abandoning his ship before all passengers and crew were evacuated. Thirty-two people are believed to have perished, including 15 whose bodies have not been found.

A statement on Codacons' website also contended that Schettino had told investigators he had taken tranquilizers but that no traces of that medication were found in either the hair or the urine.

Codacons said its experts are contending that the container holding the urine sample wasn't properly sealed. It said the results as they stand indicate a "strange, passive contamination", in which cocaine somehow got onto Schettino's hair even though he wasn't using the drug.

The prosecutor's office in Grosseto, Tuscany, was closed Saturday, as was the law office of the attorney defending Schettino, who is under house arrest in his home near Naples.

The consumer group on Friday also asked prosecutors to order DNA testing of the samples to confirm they are indeed those of Schettino, to eliminate the possibilities the samples were accidentally mislabeled or switched.

It is also seeking clarification as to which hair strands were taken, and whether they were snipped at the roots. Zerbi said the samples were taken on Jan. 17, a few days after the accident.

The Concordia's hull was speared by the reef after the ship cruised close to the island of Giglio in what many contend was a publicity stunt. Schettino has contended that the reef was not on maritime maps, but the reef is well known to sailors. He also insisted he didn't abandon the cruise liner.

The Concordia was carrying some 4,200 passengers and crew on a week's cruise on its standard route when it crashed into the reef during dinner a couple of hours after leaving an Italian port.

The boat started badly listing to one side almost immediately, causing passengers to panic and try to scramble aboard lifeboats. But the evacuation wasn't ordered until about an hour later, and some passengers jumped overboard to swim to Giglio when several of the lifeboats couldn't be deployed because of the ship's tilt.

Divers have been searching sections of the wreckage where some of the missing were last seen in hopes that more bodies can be recovered. After much delay, in great part because of stormy weather, pumping operations have been under way for a week to remove some 500,000 gallons of fuel from the ship's tanks.

The Concordia is lying on its side close to the port of Giglio, which is part of a protected Tuscan archipelago in pristine waters famed for whales, dolphins, fish and coral.