A 17-year-old Palestinian boy died following "likely prolonged malnutrition" in an Israeli prison, according to an autopsy carried out by an Israeli pathologist. The teenager, Walid Khalid Ahmad, is the first minor to have died in Israeli custody since the conflict between Hamas and Israel started in October 2023, according to the Palestinian Prisoners' Society (PPS). He died in Israel's Megiddo Prison on March 22, according to his family and a joint statement by the PPS and the Palestinian Commission of Detainees' Affairs. Ahmad was arrested on September 30 last year in his home in Silwad, a Palestinian town northeast of Ramallah in the occupied West Bank. His father Khalid said that he was detained based on alleged offenses between 2020 and 2023 that included throwing stones and Molotov cocktails. Walid and his family deny the accusations made against him. The PPS told CNN the teenager was not charged, and court hearings were repeatedly delayed. Five days after Ahmad died, his body was examined at the Abu Kabir Forensic Institute in Tel Aviv, according to a copy of the autopsy report that his family shared with CNN. The autopsy report described signs of severe weight and muscle loss, including loss of muscle mass at the temples, a sunken appearance at the abdomen and "almost absent muscle mass or subcutaneous fat on trunk and extremities." "Autopsy findings suggest that Walid suffered from extreme, likely prolonged malnutrition as observed by his deeply cachectic state and complaints of inadequate food intake since at least December 2024," it said. "It needs to be noted that malnutrition increases the risk of infectious complications including severe sepsis," it added. CNN did not receive an immediate response from the Israel security service or the Israel Defense Forces about why the teenager was arrested last September and whether he had been formally charged. The Justice Ministry referred inquiries back to the Prison Service. The PPS told CNN that Ahmad is not only the first minor to die in Israeli custody since October 2023, but also since 1967. CNN cannot verify the assertion. At least 63 Palestinians from Gaza and the West Bank have so far died in Israeli detention since the start of the latest conflict, the PPS said, including at least 40 from Gaza. The Israeli Prison Service told CNN that "upon receiving the initial report on the detainee's condition, a medical team was called to the scene and responded as required." "As in any case of the death of a prisoner, an investigative team was appointed to examine the incident. Upon completion of the investigation its findings will be forwarded to the authorized authorities," it said. Khalid, Ahmad's father, told CNN that on September 30 last year, Israeli forces "stormed the house" at around 3:30 a.m. and arrested his son. The family was allowed to attend several court hearings in the case, which were held remotely by video conference calls, he said. Israeli authorities continue to hold Ahmad's body, Khalid told CNN. The family was informed of his death on March 24, two days after he died, Khalid said, adding that days later, he received a phone call from the medical team that conducted the autopsy, who told him "the painful truth" behind his son's death. An avid athlete, Ahmad did not suffer from any known illnesses before his detention, his father said, pointing to his treatment in custody as the cause of his son's death. "Walid was a young man with great values," Khalid said. "What happened was unexpected." The Commission on Detainees' Affairs and the PPS said Walid's death was "proof of the horrific level of abuse faced by detainees inside Israeli occupation prisons, including hundreds of children." Israel has ramped up arrests in the occupied West Bank since the latest war began, PPS said, with some 15,700 arrests so far recorded by its count. — CNN