The officer's body was dragged down a Bangkok street in a hit-and-run accident.
Police took Vorayuth Yoovidhya in for questioning Monday after tracing oil streaks for several blocks to his gated estate in a wealthy Bangkok neighbourhood.
Police commander Lt. Gen. Comronwit Toopgrajank said he found the car on the compound of late Red Bull founder Chaleo Yoovidhaya, one of Thailand's wealthiest men before he passed away this year.
The officer was killed during a pre-dawn motorcycle patrol. Thai media reported that the car dragged the officer and his motorcycle for several dozen meters (feet) as it sped through the residential neighbourhood.