A military fact-finding panel looking into the controversial death of a cadet admits the 18-year-old was "disciplined" two days before he died but insists the punishment was not the cause of death.
The death was caused by sudden cardiac arrest, it said.
Pakapong "Moei" Tanyakan was hyperventilating after the punishment on Oct 16, but investigators found the actual cause of death was that his heart suddenly and unexpectedly stopped beating on Oct 17, the panel said.
It is not uncommon for students at the Armed Forces Academies Preparatory School to hyperventilate, probe panel chairman and head of the joint chiefs-of-staff ACM Chawarat Marungruang said yesterday, referring to the symptoms of muscle contraction in fingers and fast breathing.
The condition occurs when a person exhales more than they inhale, leading to a rapid reduction of carbon dioxide in the body.
On Oct 16 Pakapong went on a run but was not fast enough. He was later disciplined and failed to say the traditional "thank you" after the punishment. He was punished again before suffering hyperventilation, according to the investigation.
Pakapong was also disciplined in a classroom on Oct 15.
However, none of these punishments were harmful to life, ACM Chawarat said.
He also denied a rumour that the first-year cadet was disciplined by several senior students including one who was bitter over being dismissed as a "commander student" that stripped him of the right to carry out disciplinary measures.
On the day Pakapong died, he was in the school's medical unit and nobody disciplined or assaulted him, ACM Chawarat said.
Pakapong appeared "disturbed after talking to his parents on the phone", and also showed signs of chest pain, he said, citing footage obtained from a security camera.
ACM Chawarat suspected Pakapong may have suffered from some sort of heart disorder, though investigators ruled this out.
He would not have been admitted to the school if an existing heart condition had been found, they said.
As for a "cracked" rib, this might have occurred as four-hours of cardiopulmonary resuscitation was carried out to try to save his life while bruises found on his body probably resulted from an accident when fell down eight steps on some stairs on Oct 10, ACM Chawarat said.
He did not go into details about how and where Pakapong fell down the stairs.
The probe team plans to officially inform Pakapong's parents of its findings on Monday, following a lengthy investigation, which say up to 42 first and third-year students, commander students and military officers questioned.
Pakapong's parents still suspect their son died afteer being assaulted and his mother, Sukanya, wrote on her Facebook page this week that her family has information they plan to use as evidence when the family takes the case to court.
Earlier on Dec 8 the family received autopsy results from the Justice Ministry's Central Institute of Forensic Science which, according to Pakapong's older sister Supicha, confirmed his broken rib did not result from cardiopulmonary resuscitation.
A source closed to the family quoted Ms Supicha saying yesterday the panel's findings were not new. The family was now waiting for an examination of Pakapong's internal organs.