At around 20:00, the child was rushed to hospital, said police spokesperson Sergeant Mahlomola Kareli.

"On arrival at the hospital, medical professionals tried all they could, but the child lost his life," said Kareli.

Police were informed of the incident, and Kopanong detectives opened an inquiry.

It was soon established that the child's death had not been accidental.

"A post-mortem was conducted, and it confirmed that the child died due to poisoning," said Kareli.

The substance used to poison the child has yet to be determined, according to Kareli.

"Detectives worked tirelessly, putting pieces of information together until everything pointed to the suspect," Kareli added.

The 32-year-old man, who was in a relationship with the child's mother, was traced and arrested on Wednesday morning.

He is expected to appear in the Bloemfontein Magistrate's Court on Friday on a charge of murder.

News24