The Justice Ministry would protect all witnesses in the case, whether government officers or the public, he pledged.
The witness, Pol Col Thanasit Taengchan, from the Office of Police Forensic Science, examined the scene of the accident in 2012 and later changed his statement to revise down the speed of Vorayuth’s Ferrari from 177kph to 79kph.
The greatly reduced speed was an important factor in prosecutors deciding to drop charges against Mr Vorayuth.
Earlier this month, however, Pol Col Thanasit said he had faced pressure from senior officers and later tried in vain to change his statement back to 177kph.
Sources in the Rights and Liberties Protection Department said it had periodically advised Pol Col Thanasit about the conditions for witness protection.
Pol Col Thanasit told the department he had some concerns about who would be protecting him and also that he only wanted to be protected at certain times.
Concerns over his safety mounted after another key witness in the case, Jaruchart Mardthong, died in a motorbike accident in Chiang Mai province shortly after his evidence in favour of Mr Vorayuth was publicised.
Vicha Mahakun, chairman of an inquiry committee appointed by the prime minister, on Wednesday expressed concern for Pol Col Thanasit.
Move Forward Party MP Rangsiman Rome earlier said that, according to a House committee report, former national police chief Pol Gen Somyot Poompanmoung had introduced university lecturer Saiprasit Koetniyom, who estimated Mr Vorayuth’s speed to have been below 80kph, to Pol Col Thanasit in February 2016.
Pol Gen Somyot yesterday said he had nothing to do with the case, didn’t know the lecturer and had been in Switzerland on the day in question.
The police panel probing the alleged mishandling of the 2012 hit-and-run case wrapped up its investigation on Wednesday (Aug 19) – 20 police were found to be negligent, some of whom had since retired.
The Public Prosecutor Commission earlier this week decided not to set up a panel to investigate Deputy Attorney-General Nate Naksuk over his decision to drop Mr Vorayuth’s reckless driving causing death charge. It said the proposed panel would only be duplicating another panel’s work.