Codacons said Saturday that some traces of cocaine were found on a hair sample and in an envelope containing the sample, but noted that a urine sample taken from Schettino and an analysis of the hair itself found no presence of the drug. It called that finding "very strange" and said it had asked prosecutors on Friday to order new testing to see if the samples might have been contaminated.
The Italian news agency ANSA quoted the forensic medical expert who carried out the toxicology test as dismissing Codacons' concerns about the external trace of cocaine.
The expert, Marcello Chiarotti, was quoted as saying the trace of cocaine "was a marginal problem that absolutely doesn't invalidate the results of the analysis," which found none of the drug inside the hair itself or in the captain's urine. Traces of cocaine in the urine or inside the hair itself would have pointed to consumption.
Schettino is under house arrest in his home near Naples while he is investigated for alleged manslaughter, causing a shipwreck, and abandoning his ship. He has denied abandoning ship and insisted the reef was not marked on navigational charts.
Thirty-two people are believed to have died, including 15 whose bodies have not been found.
In Minnesota, the only Americans lost in the disaster were remembered Saturday as a faithful couple and loving grandparents who spent their final moments as they had much of their lives - together.
A memorial Mass for Jerry and Barb Heil drew hundreds of people to the couple's longtime Minnesota church in White Bear Lake, a suburb of St. Paul. The Heils are among the 15 people still listed as missing.
"After a tragedy such as this, it's normal for us to feel a little empty," their son Nathan Heil said during a service that also featured readings and prayers by several of the Heils' grandchildren. "But things will get better with time, Mom and Dad would always say, and usually they were right."