Johor Baru (North) deputy police department chief Superintendent Mohd Akhir Ishak said initial investigations show that Siwakorn Sukuntha had been abused right up to an hour before he died.

The police have already detained the boy's Singaporean stepfather, 31, and his Thai mother, 32, for further investigations.

The couple - whose names have been withheld by the police - are in remand until Jan 3.

The family lived in a rented three-bedroom apartment in the Pulai View Condominium in Tampoi, Johor.

The police believe the boy had been repeatedly abused by his stepfather for three or four days before his death. Injuries were found on his body, hands, legs and head.

According to security guard supervisor Indra Prasad, the boy's frantic mother ran to the condominium's security guard post at about 2.30pm on Saturday pleading for help.

'She told me something had happened to her son and to call for an ambulance,' Mr Prasad, 38, told The Straits Times yesterday.

The Nepalese guard followed the woman up to her unit.

There, he saw the diminutive boy, wearing just a pair of shorts, lying motionless on a bed in one of the rooms.

Mr Prasad said the stepfather was standing in a corner of the room.

Bruises and lash marks could be seen all over the boy's body and face, and his eyes were swollen.

A patch of blood had also soaked the mattress near where Sukuntha's head lay. Blood was also trickling from his ears.

'I felt his wrist, but it was cold. I knew he was dead,' Mr Prasad recalled.

He immediately contacted a fellow security guard, Mr Sanjay Kumar, 27, via the intercom and instructed him to call the police as well.

In the 10 minutes before the ambulance came, Mr Prasad said the boy's mother wept while his stepfather was silent.

He said the barechested man simply told his wife in English to let her parents in Thailand know.

Mr Prasad said the family had been living in Pulai View for about seven months. The boy did not appear to go to school, and was often with his mother.

Johor police say the stepfather was a factory operator in Singapore who was retrenched recently. He also has a six-month-old baby girl with his wife.

Their monthly rent was about RM1,200 (S$500), Mr Prasad estimated.

He added that he last saw Sukuntha about three days ago, swimming in the condominium pool, as he often did. He did not see any injuries on the child then, he said.

'Every day they go in and out (of the condominium) and then suddenly the boy is dead,' he said.

Mr Kumar said the family had always appeared to be loving.

But one resident, who did not wish to be named, said the man had been heard shouting occasionally.

The couple are not Malaysian permanent residents but had proper travel documents.

Johor police believe the last time the boy had been harmed was at about 1pm on Saturday. He died at 2pm.

His body was taken to the nearby Sultanah Aminah Hospital for a post-mortem. It is understood that it was claimed on Sunday by the boy's natural father.

carolynq@sph.com.sg