The head of a House committee has alleged a forensic police officer admitted to him he was following orders when he made a low assessment of the speed of Red Bull heir Vorayuth Yoovidhya's supercar when he hit and killed a motorcycle policeman in 2012.
Sira Jenjaka, chairman of the committee on law, justice and human rights, said on Friday that Pol Col Thanasit Taengchan of the Office of Police Forensic Science had told him in person that he would tell the House committee who had ordered him to make the assessment.
"But when he was there [before the committee], he only said that a commander brought Mr Saiprasit to him," Mr Sira said, referring to Saiprasit Kerdniyom, head of the Automotive Safety and Assessment Engineering Centre at the King Mongkut's Institute of Technology North Bangkok.
On Thursday Pol Col Thanasit told the House committee that he changed the assessed crash speed of Mr Vorayuth's Ferrari car from 177 kilometres per hour to 79kph based on the calculations of Mr Saiprasit.
The revised speed assessment was cited as the main reason police and public prosecutors decided not to arraign Mr Vorayuth, known as Boss, on a charge of reckless driving causing death.
"Pol Col Thanasit's conclusion has an impact on the case... I urge Pol Col Thanasit to tell the truth," Mr Sira said. He also called on the national police chief to ensure the safety of Pol Col Thanasit.
"We wonder if Pol Col Thanasit could be in danger, like a witness in the case who was in Chiang Mai," Mr Sira said, referring to the recent death of the witness.
He said his committee would call Mr Saiprasit in to testify.
Mr Vorayuth, 35, also known as Boss, was driving the black Ferrari that hit and killed Pol Snr Sgt Maj Wichian Klanprasert, 47, of Thong Lor police station, in the early morning of Sept 3, 2012.
He crashed into the rear of the man's motorcycle on Sukhumvit Road, the fled the scene to his parents' home nearby.
With the help of a team of lawyers, he delayed hearing charges seven times. It was not until April 27, 2017, that prosecutors finally charged him with reckless driving causing death and failing to help a crash victim.
He fled on a private plane two days before he was to answer the charges.
A speeding charge was later dropped when the one-year statute of limitations expired. A second charge, failing to stop and help a crash victim, expired on Sept 3, 2017.
The third and most serious charge, reckless driving causing death, would have remained on the books until 2027, but prosecutors dropped the charge in June.
Mr Vorayuth is the son of Chalerm Yoovidhya, whose family co-owns the energy drink megabrand Red Bull and ranks second on Thailand's richest list, with net worth estimated at US$20 billion (about 617 billion baht).