A six-year-old boy found dead in a car in Trat's Laem Ngop district on Sunday was killed by his mother and not his stepfather as first thought, police said on Wednesay.
The boy was found in an old Honda sedan belonging to his stepfather, who later confessed to beating him and leaving him to die in the vehicle.
However, an investigation ordered by assistant national police chief Pol Lt Gen Surachate Hakparn found the boy's mother killed him.
She used a wooden coat hanger to beat the boy hard across his head and body until it broke, Pol Lt Gen Surachate said yesterday.
An autopsy suggested the boy had suffered beatings on a number of occasions but the latest one saw him sustain a fractured skull, he said.
Pol Lt Gen Surachate said the mother finally admitted to beating the boy on Saturday night after he had defecated in the car. Both parents will face murder charges.