The FBI is investigating the death of a newborn found aboard a Carnival cruise ship that has returned to Port Canaveral, Fla.

Special Agent Dave Couvertier wrote in an email to The Associated Press that the FBI's Evidence Response Team was activated Saturday morning when the ship returned to its Florida base. He said the FBI is working with port authorities to investigate.

Florida Today reported on its website Saturday evening that an employee of the Carnival Dream ship found the dead newborn in a guest cabin. The newspaper reported that Carnival officials said the cruise line informed authorities in St. Maarten and that the mother, a 20-year-old U.S. passenger, was detained.

Couvertier said no one has been charged, and that he understands the mother hasn't returned to the U.S.