Chris O'Meara / AP The marble was found in one of the grave sites.

The remains of a total of 55 students have been found on the campus of a now-shuttered reform school infamous for its brutal treatment of young boys, many of whom are believed to have died under mysterious circumstances.

Researchers excavating graves at the Arthur G. Dozier School for Boys in Marianna, Fla. said Tuesday they have found more bodies than originally thought in the school’s cemetery. A 2009 investigation concluded there were 31 boys buried there, but the new body count nearly doubles the number, reports the Wall Street Journal.

The reform school opened in 1900 and closed in 2011, having acquired notoriety for its harsh treatment of students. Over its history, the school faced allegations that students suffered beatings, rapes, and forced labor, but school officials repeatedly denied wrongdoing despite a series of state and federal investigations.

Students who died at the school often were buried in unrecorded locations, and the cause of death was often listed as “unknown.” School officials told student George Owen Smith Dozier’s parents their son had disappeared and was found dead of pneumonia. When the parents asked the school to keep the body so they could retrieve it, the school buried him before they arrived, his sister told the Journal.

Researchers are seeking relatives of the boys to submit DNA samples to compare with the remains.

[WSJ]