Police announced the closure of the "Natpong" case, concluding it was a suicide. CCTV footage inside the residence aligns with witness testimonies. No one caused death by poison. Autopsy revealed burns from the tongue surface extending to the stomach.
At 11:00 AM on 13 Dec 2025 GMT+7, at Bang Kruai Police Station, Nonthaburi Province, Pol. Lt. Gen. Watthana Yijin, Commander of Region 1 Police; Pol. Maj. Gen. Atthaphon Anusit, Deputy Commander of Region 1 Police; Pol. Maj. Gen. Worachat Saenkham, Commander of the Investigation Division, Region 1 Police; Pol. Maj. Gen. Decharapee Khongdee, Commander of Nonthaburi Provincial Police; Pol. Maj. Gen. Sujetana Sotthipan, Commander of Forensic Unit 1; Pol. Col. Prathan Nantakob; Pol. Col. Witit Chan-iem, Deputy Commander of the Investigation Division; Pol. Col. Poonsuk Techaprasertporn, Superintendent of Division 1, Region 1 Police; Pol. Col. Kittisak Pongthanarak, Superintendent of Bang Kruai Police Station; and Pol. Col. Supachai Srisak, Superintendent of the Investigation Division of Nonthaburi Police jointly held a press conference on the death of Mr. Nattawut Ponglangka, aka Natpong, a Channel 8 reporter.
Pol. Lt. Gen. Watthana Yijin stated that after interviewing four witnesses inside the deceased's home and one who removed evidence from the scene, authorities learned of an additional person who brought cyanide to the deceased. All involved were thoroughly interrogated. Investigations traced the cyanide’s origin to Mr. Kitti, an employee at a gold shop, who illicitly brought it out and gave it to the deceased. Tests at the deceased’s residence confirmed it was the same cyanide. No other person was found handling or involved with the cyanide packet found in the death room. Thus, the conclusion is that the deceased committed suicide. The family accepted the police's case closure.
Pol. Maj. Gen. Worachat Saenkham said that after cyanide was found in the deceased's body causing death, Region 1 investigators reviewed CCTV footage inside the housing estate to identify involved persons and reconstruct events. On 7 Dec 2025 GMT+7, four people who drank with the deceased and one close associate gave statements and handed over the deceased's mobile phone. Police reviewed the CCTV footage accessible via the phone to verify witness accounts. There were 10 cameras inside the house covering the front yard, living room, and stairs to the second floor, but the room where the deceased died could not be accessed on camera.
The CCTV footage that police reviewed matched the statements of all five witnesses, showing consistent timelines, movements inside the house, and entries and exits. On 8 Dec 2025 GMT+7, Mr. Kitti met with investigators to admit bringing cyanide to the deceased. Police verified CCTV showing he delivered it on 29 Oct 2025 GMT+7, placing it on the central table. Later, Mr. Theerapong, aka Big, a friend of the deceased, moved it to the room where the deceased was found dead.
On 11 Dec 2025 GMT+7, Region 1 investigators, along with forensic and investigative police, inspected the death scene and reviewed the CCTV inside the deceased’s room. They found footage of the deceased retrieving the cyanide packet from under the computer table, holding it for about 40 seconds before returning it. Afterwards, the group drinking inside left, leaving only Big, Ton, and the deceased. At 08:39 AM, the deceased was found dead inside the room. The 10 CCTV cameras’ footage aligned with statements from six witnesses and close associates, all consistent.
Pol. Maj. Gen. Sujetana Sotthipan said that after Forensic Unit 1 was notified to assist in the home inspection per Mr. Kitti’s statement, officers collected cyanide samples found both at the gold shop and the deceased’s home, confirming they were the same. Regarding how the cyanide entered the deceased’s body, earlier CCTV from 8 Nov 2025 GMT+7 showed Mr. Big placing the cyanide packet on the computer table in the deceased’s room. On 30 Nov 2025 GMT+7, the day of death, footage showed the deceased took the cyanide packet from the table, was absent for 40 seconds, then returned it.
Pol. Maj. Gen. Sujetana added that the cyanide tested was potassium cyanide, matching samples illicitly brought by Mr. Kitti from the gold shop and consistent with the packet found on the computer table. Vomit found in the death room also tested positive for potassium cyanide.
Regarding earlier claims that the cyanide was gold cyanide, the forensic unit did not confirm this. The medical examiner found burns on the tongue surface, mid-tongue, and base extending to the stomach, indicating direct contact with a highly concentrated substance, ingested orally.
Pol. Maj. Gen. Atthaphon Anusit concluded that after thorough investigation, police found no motives or reasons for anyone to harm the deceased. Evidence including the cyanide packet and CCTV inside the house showed no other person handled or was involved after the deceased took the packet and was absent for 40 seconds before returning it. The deceased then died in the room, with no indication that anyone else caused death by poison.