Former national police chief Pol Gen Somyot Poompunmuang and Nate Naksuk, a former deputy attorney-general, did mishandle the infamous 2012 hit-and-run case, National Anti-Corruption Commission (NACC) chief Niwatchai Kasemmongkol said on Wednesday.
The case involved Vorayuth "Boss" Yoovidhya, the scion of the family behind the Red Bull empire.
Education Minister Pol Gen Permpoon Chidchob, who served as an assistant national police chief at the time, was also found guilty but on a less-serious disciplinary charge, said Mr Niwatchai.
He was citing an NACC decision on Tuesday to formally accuse a number of people it found were involved in mishandling the case.
"A formal press briefing will be held soon to explain the decision in detail," he said.
Nate: Was deputy AG
According to a source familiar with the matter, 15 people -- mostly current and former police officials -- were formally accused by the NACC.
In the early hours of Sept 3, 2012, Mr Vorayuth crashed his Ferrari into a motorcycle driven by Pol Snr Sgt Maj Wichian Klanprasert, in the Thong Lor neighbourhood.
Instead of stopping to help the victim, Mr Vorayuth, then in his early 20s, drove off, dragging the victim's body about 200 metres from the scene of the accident. He did not report it.
After repeatedly ignoring orders to appear in court, he fled the country in 2017. The statute of limitations on some charges have already expired.