A baby has died as a teenage boy and a woman have been arrested.
Emergency services raced to the property in the town of Belper on Sunday just before 10.50pm following reports a baby was hurt.
East Midlands Ambulance Service and Derbyshire Police found the baby in cardiac arrest. The child was taken to hospital but died on Wednesday afternoon.
A 21-year-old woman and a 16-year-old boy were arrested on suspicion of assault in connection with the incident.
They have since been released on police bail pending further investigations.
Detectives have been in the area for several days carrying out investigations and speaking to people about the circumstances which led to the death. A scene remains in place.
A Derbyshire Police spokesperson said: “We received a call just before 10.50pm on Sunday 2 January to report that East Midlands Ambulance Service where in attendance at an address in Acorn Drive, Belper, where a young baby was in cardiac arrest.
“The child was taken to hospital, but tragically died yesterday afternoon (Wednesday 5 January).
“Detectives have been in the area for several days carrying out enquiries into the circumstances which led to the death, and a scene remains in place.
“A 21-year-old woman and a 16-year-old boy were arrested in connection with the incident and have been released on police bail pending further investigations.”