Police in Thailand say they have begun the process of requesting an arrest warrant for an heir to the Red Bull energy drink fortune who was accused of a deadly hit-and-run accident almost five years ago but was never charged.

National police chief Chaktip Chaijinda announced the effort to arrest Vorayuth (Boss) Yoovidhya in Bangkok on Friday — one day after the attorney general's office said it would seek a warrant if Yoovidhya again failed to appear in court.

Thursday marked the eighth time he has missed a summons since legal proceedings against him began in 2016. Police must submit a request for the warrant to a court, which decides whether to issue it.

The case has raised questions about whether the Thai justice system favours the rich and famous, allowing them to break the law with impunity.

Vorayuth was charged with speeding, hit and run and reckless driving in the death of the policeman in 2012.

"He sent a letter requesting to move the appointment but he can't do this again," said Suthi Kittisuppaporn, director general of the attorney general's Department of Southern Bangkok Criminal Litigation, on Thursday.

Attempts by Reuters to reach a lawyer for Vorayuth went unanswered.

Vorayuth is a grandson of the late Chaleo Yoovidhya, creator of the Krating Daeng, or Red Bull, energy drink.

Police examine a damaged Ferrari at the home of the late Red Bull founder Chaleo Yoovidhaya in Bangkok in September 2012. (Stringer/Reuters)

Whereabouts unknown

Chaleo, 88, was listed as the third richest person in Thailand at the time of his death in 2012, with an estimated net worth of $5 billion US, according to Forbes magazine.

His grandson, Vorayuth, who has spent much of the past five years abroad, including in London and Singapore, according to social media posts, has previously cited work commitments abroad as reasons for not showing up in court.

Reuters was unable to confirm Vorayuth's whereabouts. Some media reported he was in Britain.

In 2012, Vorayuth allegedly crashed his Ferrari into a policeman on a motorcycle in Bangkok's upscale Thonglor neighbourhood.

He is accused of fleeing the scene, dragging the officer's body for several dozen metres with his car as he did so.

Vorayuth's speeding charge expired a year after the crash. The charge of hit and run carries a penalty of up to six months in jail and expires in September while the reckless driving charge carries a maximum penalty of 10 years of jail and expires in 10 years, if left unchallenged.