A Brazilian doctor charged with killing seven patients to free up hospital beds for those with private health insurance may have been responsible for 300 deaths in total, the country's health ministry has said.
Officials investigating Virginia Soares de Souza (56) are reviewing more than 1,800 medical records at the hospital where she was the head of intensive care since 2006.
If the number of deaths suspected of being linked to Ms de Souza is proven, she would have been a more prolific serial killer than the British doctor Harold Shipman, who was found to have killed at least 215 people.
Dr de Souza, a widow who worked at the Evangelical Hospital in the city of Curitiba, the capital of the southern state of Parana, is accused of masterminding a "gang of death" involving several members of her medical team.
Three anaesthetists – Edison Anselmo Silva Junior, Maria Israela Cortez Boccato and Anderson de Freitas – were also arrested last month while another 13 doctors and 34 nurses have been transferred out of the department.
Dr de Souza is suspected of giving patients the muscle-relaxing drug Pavulon and turning off their oxygen machines. One nurse interviewed on Brazilian television, who worked in the hospital from 2004 to 2006, said she saw Dr de Souza turn off a life-support machine, killing a patient.
Marcus Michelotto, inspector general of the Civil Police of Parana, said: "We have been investigating this for about a year."
According to the Brazilian Press, the case came to light after a complaint was made to the health watchdog last year. Since then, at least 50 other complaints have been filed.
Dr de Souza denies the charges and defended her record at the hospital where she has worked since 1988.