Tainan: An autopsy conducted on a 13-year-old boy who died in February amid allegations of school bullying found no signs that he was poisoned, concluding instead that he died from complications related to a viral infection, Tainan prosecutors said Thursday.

According to Focus Taiwan, the Tainan District Prosecutors Office stated that an autopsy and toxicology report by the Ministry of Justice’s Institute of Forensic Medicine found no traces of drugs or toxins in samples of the boy’s hair, blood, and urine. The boy’s cause of death was determined to be myocarditis, or inflammation of the heart, and heart failure, which were caused by a viral infection.

The autopsy results were presented to the boy’s family, which requested further investigation. The office affirmed that it would put “full efforts” into probing whether any illegal activities took place. Meanwhile, the Tainan Bureau of Education reported that an external investigation found no evidence of bullying. The probe, conducted by a committee of special education teachers, psychologists, and lawyers, was based on relevant evidence and witness interviews. It concluded on April 8 and its findings were distributed to students’ parents on April 14.

The case gained attention on Feb. 27, after the boy’s mother posted on Facebook that her son, a seventh-grader at Houbi Junior High School, had died on Feb. 24. She claimed a hospital blood test indicated “signs of poisoning from a toxic substance” and alleged that her son had been bullied and force-fed drug-laced coffee powder by classmates.

The school’s principal stated that the student had not attended school since Feb. 20 due to illness and that he only learned of the boy’s death from his parents. The Education Bureau, in its statement, confirmed that all 164 students at the school were tested for drugs on March 10, and all results were negative.