A man and woman will appear in the Pretoria Magistrate's Court on Thursday on charges of murder and child abuse, following the death of their two-month-old baby.

Captain Tessa Jansen said the parents rushed their baby boy to Steve Biko Hospital on Saturday after he had convulsions.

"The baby was admitted. The mother and father were interviewed by the doctor after he saw blue marks healing on the baby's body."

Jansen said when the doctor informed the couple, of Valhalla in Pretoria, that he intended to call in social workers, the 30-year-old mother blamed her seven-year-old son for the bruises.

She said her son had been playing rough with the baby.

"The baby died on Tuesday and a preliminary autopsy revealed that he was killed by bleeding in the brain. The woman and her 27-year-old lover were arrested," Jansen said.

The seven-year-old son was removed from his parents and taken to a place of safety.