NT Police are investigating the circumstances around the death of a 39-year-old Humpty Doo woman who was taken to Royal Darwin Hospital on Monday morning after falling “seriously ill”, with a man known to the woman later arrested.

Police said in a statement on Monday evening that emergency services and St John Ambulance attended to reports the woman had become “seriously ill” at a Humpty Doo residence around 9am Monday morning.

The woman was conveyed to the hospital by St John in a critical condition and later passed away, police said.

“Police attended the hospital and have since commenced an investigation into the circumstance of her death,” police media director Mark Wilton said in the statement.

“A crime scene has been established at a rural residence.”

A 39-year-old male, who police said is known to the woman, was arrested on Monday and is “assisting police with enquiries”.

No charges had been laid as of last night.

“Investigations remain ongoing into the exact circumstances and cause of the woman’s death,” Mr Wilton said. “Police will release further information as the investigation progresses.”