The Independent Office for Police Conduct (IOPC) is investigating Derbyshire Constabulary interaction with a man who died after a ‘short period’ in custody in Chesterfield.
The 42–year-old man - who has not yet been named - became unwell shortly after arriving at Chesterfield custody suite at around 1.30pm on Sunday, January 7, following his arrest in Pleasley during a domestic incident.
Just before 3pm, the man was transferred by ambulance to Chesterfield Royal Hospital where he sadly died on Wednesday night.
A Derbyshire Constabulary spokesman said: "We would like to offer our condolences to the family and friends of the man who died.
"We are assisting the IOPC with their investigation into the circumstances surrounding the incident, and supporting our officers, staff and anyone affected by it."
An IOPC spokesman said: "All deaths and serious injuries in police custody must be referred to the IOPC by law.
"Following the referral from Derbyshire Constabulary, IOPC investigators were deployed to the post-incident procedures on Sunday.
"We are reviewing CCTV footage from the custody suite and body-worn video.
"Police officers and staff who had contact with the man or witnessed his detention have provided us with their initial accounts of the incident - and investigators have contacted the man's family to explain our role."
The coroner has been informed about the incident and a post-mortem examination is due to take place over the weekend.
IOPC regional director Derrick Campbell said: "Our sympathies are with the man's family and everyone else affected by his death.
"Our inquiries are at an early stage and we will be carrying out a thorough investigation into the events of Sunday."