He was brought to re-enact the crime at three locations – the school where he picked her up, a wooded area where he attacked her and a location where he disposed of her body – yesterday afternoon, while 100 policemen protected him from an angry crowd.

The man faces charges of murder, disposing of the body to conceal the crime, sexual assault and taking a minor under 15 from her parents to commit a lewd act.

The girl’s body, found on Wednesday night behind a construction workers’ camp four kilometres from her home, is undergoing an autopsy at Bangkok’s Institute of Forensic Science at Police General Hospital.

Her father said that the medical examiner cited the girl’s cause of death as drowning but could not say if her head had been held under water or thrown into the water.

Wichai was detained on Wednesday after his motorcycle was identified as matching the one seen in CCTV surveillance video picking up the Prathom 5 student from school the day before. After hours of interrogation,

Wichai confessed to sexually assaulting and suffocating her when she screamed for help and tried to escape.

He also claimed he attacked the girl after she called him loong ja, an endearing way to say “uncle”. After killing her, he hid her body

in bushes about four kilometres from her home – and removed her clothing to try and prevent her from being recognised.

“I was drunk at the time. I would like to apologise to the girl’s parents for what I did out of impulse and alcohol influence despite the fact that we are best friends,” he said.

The victim’s father, 64, said: “I never thought he would do this to my daughter – I had asked him to pick her up from school twice before. Now he confessed to the crime so I will let justice run its course. If I have a chance, I will ask him how he could have done such a thing to my family.”

The girl’s mother, 50, said: “If I have a chance to talk with him, I will slap his face and ask why he did this to my daughter.”

The girl was their only child.