Responding to a reported homicide early in the morning, police found Wasan Natthaya lying in a pool of blood on a footpath near the Phra Khanong intersection, while his 43-year-old father Subin Natthaya sat nearby.

Police also found the murder weapon, a bloodstained metal pipe, and a six-inch knife nearby. Witnesses said Wasan - chased by his pipe-wielding father from where they lived in Soi Phumjit - fell down and Subin hit the boy until he was dead, despite his pleas for his life.

Subin told police he lived with two sons at a campsite in the soi for eight years after he split with his wife. Wasan was a bad boy, never lending a hand with the chores and only interested in computer games.

Wasan had told Subin that he would become a spirit medium, boasting he was immortal and could not be injured by knives.

So he stabbed the boy in the neck but the knife broke and the boy ran away.

"When he fell down, I started to beat him and then, fearing that he would suffer from the injuries, I decided to kill him.

"I did it because he was a bad boy and I couldn't take care of him on my own. I have had a difficult life and raising him was getting too much, so I decided to kill him," Subin told police.

Subin was charged with murder and has been sent for psychiatric test as well as tests for drug abuse.