A car driving instructor, who fled right after a crash which killed a highway policeman in Pathum Thani on Thursday evening, surrendered to police later that night.
The crash happened at a bridge in Lam Luk Ka district around 6.30pm.
Police and rescue workers at the scene found Pol Sgt Setthakarn Loykhampom lying dead.
A badly damaged police motorcycle was about 100 metres away from the officer, and a black Toyota Vios was nearby with extensive damage to its front left side. An opened bottle of beer was found inside the car, but the driver was not found.
Witnesses told police that they saw the police motorcycle chasing the black car. When reaching the scene, the car hit the police bike, which fell to the ground. The car then hit concrete barriers, causing it to stop there. The driver was seen getting out of the car and fleeing down Lam Luk Ka road.
Kittirat Ranprasit, the driver involved in the crash, reported to police about two hours later.
Mr Kittirat, a car driving instructor, was taken for alcohol and urine tests.
During questioning, he told investigators that he parked his car along a motorway to fish at a nearby swamp. At the time, the highway police officer arrived and asked him not to park his car in this non-parking area.
When the officer tried to search his car, Mr Kittirat said he tried to flee because there was a bottle of beer and an e-cigarette inside his vehicle, and he was afraid of being arrested at the time.
As the officer gave chase, the driver said he was frightened and sped off, causing his car to hit the officer.