A quick-thinking boy of nine has prevented a stranger from stealing his newborn brother from a hospital ward.

The child stepped in after a 34-year-old woman picked up the day-old baby and took it from the room where the mother was sleeping.

He followed out the would-be abductor and spoke to her, at which point she handed the baby back, police said.

The unnamed woman was arrested and taken to a psychiatric clinic.

Police said the boy's act had "significantly" contributed to the baby's safe return at a hospital in Hamburg, Germany.