The dismembered bodies of more than 100 prisoners were discovered Wednesday in the drain pipes of one of the largest prisons in Bogota and surrounding jails, Reuters reported.

“The number of victims is unknown, but we know it’s over 100 and could be considerably higher,” Caterina Heyck, an investigator at the attorney general’s office told the news agency. “Remains of prisoners, visitors and others were thrown in the drainage system.” reported that the bodies appeared to have been dismembered between 1999 and 2001 and were reportedly described as “recluses, visitors, persons from outside the prison, whose remains were thrown into sewage ducts.”

The report said the jails in the country are some of the most overcrowded in Latin America.

“The horrors of what happened in that prison should be analyzed in a criminal investigation, but also call for a deep reflection within Colombian society,” Heyck said.