A teenage girl of 15 has been arrested by the police for the murder of his half brother.
German police have arrested a 15-year-old girl accused of killing her three-year-old half brother, a police spokesman in the city of Bielefeld said on Thursday.
Investigators think the teenager inflicted fatal injuries on the child on Wednesday night, the police said in an earlier statement.
She then fled the scene and an intensive search followed, using dogs and a helicopter.
There is no clear motive why the alleged stabbing took place, police have said.