A 26-year-old woman, who collapsed at an illegal rave in Thetford after apparently taking a cocktail of drugs, remains in hospital.
The woman was air lifted to hospital for treatment on the weekend. She had been at a music event near Fire Ride 62, off the Wrentham Road in Croxton.
Officers received reports of loud music being played at this remote location at around midnight (Saturday 20 July).
As police worked to disrupt the event, officers were called to the woman who had collapsed and was fitting.
Between 200 to 300 people, arriving in over 60 vehicles, had been at the event.
Seizure of various items of sound equipment including speakers, mixing decks and a generator also took place.
The woman remains in a stable condition in intensive care.
Chief Superintendent Nick Davison, Norfolk's County Policing Commander, said: "Norfolk Constabulary has a zero tolerance approach to unlicensed musical events.
"We warn people attending that they are potentially dangerous and cause unnecessary damage as well as disruption to the local community.
"The collapse of this young woman, whose treatment proved challenging due to the remote location, should serve as a warning to other people considering holding or attending UMEs that these events can have potentially tragic consequences."