A man has been charged two months after a newborn baby he was caring for allegedly suffered fatal injuries.

Shane John Marshall, 50, of Parafield Gardens in Adelaide, has been charged with murder after the seven-week-old baby was taken to Women and Children’s Hospital on July 24.

Police say the child sustained injuries later that day at a home in the northern suburbs, The Advertiser reports.

The baby died six days later, leading to South Australian Police treating it as a serious crime the same day.

After an extensive investigation, detectives with the Major Crimes Unit arrested Marshall on Wednesday and charged him with one count of murder.

Police will allege Marshall inflicted the injuries on the child while in his care on the same afternoon the seven-week-old baby was rushed to hospital.

The boy’s identity was kept secret by the court.

Marshall appeared in the Adelaide District Court on Wednesday afternoon via video link and sat quietly throughout the hearing.

Shane John Marshall, 50 (pictured) has been charged with murder after a newborn baby he was caring for died

The court heard it took police several months to complete the case against him, the Advertiser reports.

Prosecutors told the court they would need at least four months to prepare their case against the 50-year-old.

Marshall’s attorney, Kate Opolski, asked Judge Roderick Jensen to release her client on bail.

Prosecutors did not oppose the bail request and a judge agreed to release Marshall from custody, citing the time he would have to spend in custody if the case went to trial.

Marshall was released on $1,000 bail and strict conditions.

He must live at his parents’ address, have no contact with certain individuals, and must report to a prison.

Shane John Marshall (pictured) appeared in court on Wednesday and was released on bail

Marshall didn’t have much to say. He left the field surrounded by media crews, trying to shield his face with a reflective vest.

“No comment,” a reporter who was a supporter of the event was told.

Marshall will return to court in January.