A 37-year-old man has been arrested after a two-month old baby boy suffered a head injury in Bamford.
Paramedics and an air ambulance were called to an address on Steward Gate, Bamford at about 3.20pm today (Thursday)
The boy was taken to hospital by air ambulance with a head injury.
A Derbyshire police spokesperson said: "People living in the area will have seen a large number of emergency services staff, including police, throughout the afternoon.
"We understand that members of the public may be alarmed by the news but our investigation is in its very early stages. We will circulate any updates when appropriate to do so.
"Please be assured that our continued presence this evening is part of that ongoing investigation into the circumstances."
A 37-year-old man was arrested in connection with the incident this afternoon and remains in police custody.
Anyone with information should call 101 and ask to speak to DS 2438 Ed Mellor, from the public protection unit, quoting incident 817 of June 27.