A man will appear in court on Friday charged with the murder of his baby son.
Police were called after the seven-month-old boy was taken into the Royal Derby Hospital on Tuesday.
The boy, from Waterford Drive, Chaddesden, Derbyshire, was transferred to the Queen's Medical Centre in Nottingham, where he died late on Wednesday night.
A 37-year-old man was arrested on Wednesday afternoon and has been charged with murder, police said.
He will appear before Derby Magistrates Court today.
A post-mortem examination was held yesterday to determine the cause of the boy's death.