Inside a once-secret detention center where political dissidents were tortured and killed during Argentina's dictatorship 25 years ago, forensic anthropologists have discovered a pit containing 10,000 bone fragments.

The first discovery of human remains inside a detention center confirms the testimonies of hundreds of survivors who have said for years that authorities tortured, killed and burned the bodies of political opponents, they said Tuesday.

"This scientifically confirms the testimonies of the detained," said Luis Fondebrider, a forensic anthropologist who helped uncover the remains inside the former detention center in La Plata known as Arana.