An investigation is under way into the “suspicious” death of a Birmingham toddler who was known to social services.

Police were questioning the two-year-old boy’s 24-year-old mother and her partner, aged 29, on suspicion of his murder.

They were last night “helping police with their inquiries” after detectives were given more time to question them.

The child was known to Birmingham City Council’s social services department and other agencies, an authority spokesman confirmed.

City child safety experts launched a review into the death.

The boy, who was not named by police, was taken to hospital from an address in Ward End at 7.42pm on Sunday. He was pronounced dead a short time later.

Forensics officers were seen at an address in Old Moat Way and police confirmed it was connected to the investigation.

A post-mortem examination carried out by a Home Office pathologist revealed the child died of “non-accidental injuries”. West Midlands Police said they were not releasing the cause of death for investigative reasons.