Authorities said from 2006-13, Virginia Helena Soares de Souza ordered fellow doctors to administer lethal doses of anesthetics, sedatives and painkillers to kill patients, as well as to change oxygen levels, leading to death by asphyxiation.
Souza was arrested in February but was released from jail. She was in court Wednesday as part of court-mandated monthly appearances to avoid going back to jail, CNN reported Thursday.
Prosecutors allege Souza killed the patients without their families' consent to free up beds in the intensive care unit at a hospital in Curitiba and clear up the "clutter" the patients were causing.
Mario Lobato, a doctor tasked by the Health Ministry to investigate the case told TV Globo the number of deaths could be higher. He is evaluating the charts of more than 1,700 patients and interviewing other doctors who worked with Souza.
Seven other healthcare professionals face charges in the case, CNN reported.