Three police officers are being investigated after a man died following an incident at Pontins Holiday Park in Lowestoft.
Paul Reynolds (also known as Paul Gladwell), from Colchester, was arrested after the incident on February 14.
On his way to custody Suffolk Police officers became concerned for his wellbeing and contacted an ambulance.
He was taken to hospital but later died on February 16.
The IPCC launched an independent investigation into the contact between Mr Reynolds and Suffolk Police.
Three police officers have now been served with gross misconduct notices and will be investigated criminally for misconduct in public office and health and safety failings.
Suffolk Police is conducting a parallel investigation into the actions of the security staff, who were involved in detaining Mr Reynolds up to the point when officers arrived. No arrests have been made at this time.
Anyone with information regarding this incident should email the IPCC at firstname.lastname@example.org or call 0800 096 9078.