The Police were called at around 11.30am on Wednesday 12 September following concerns for the welfare of a woman in Bideford at an address in Bridge Street, Bideford.
While at the address, some officers complained of feeling unwell and were immediately removed from the scene and a cordon put in place.
The ambulance Hazardous Area Response Team (HART) attended and treated these officers, all of whom were unharmed and have since returned to duty.
Following searches within the property, a number of items were found which required expert analysis from specialist officers and an Explosive Ordnance Disposal (EOD) team.
The house was evacuated while enquiries were ongoing. A 73-year-old man was detained and Police confirmed he was arrested under the Explosives Act.
The man has since been released and no further action will be taken in relation to this incident.