The Aruban Public Prosecutor's Office said testing by the Netherlands Forensic Institute in The Hague "excludes the possibility that the bone material found in Aruba is that of Natalee Holloway."
Spokeswoman for the Aruba prosecutor's office, Ana Angela, said police Monday obtained a second bone found on the beach earlier this month by a New Jersey family, CNN reported Tuesday.
"It does not appear to be human," said Richard Roy, general manager of the Westin Hotel.
Holloway was last seen in the early hours of May 30, 2005, leaving a nightclub with local resident Joran van der Sloot and two other men.
Van der Sloot was detained twice but never charged in Holloway's disappearance.
He is currently awaiting trial in Lima, Peru, on a homicide charge in the death in May of Peruvian student Stephany Flores.