The emergency declaration was made just after 10am after reports an armed person had been spotted inside a home on Maple Street in Marsden.
Officers helped three people leave the home, and were told one person was still inside the home with a firearm.
Police made the emergency declaration and then several hours later, confirmed no one else was inside the property.
The emergency declaration was then revoked and a crime scene has been established at the property.
Police are speaking to the three people initially escorted from the address and attempting to substantiate the report of the armed person.
Anyone with relevant information or CCTV or dashcam from the area this morning is urged to come forward.
Police had been called to an unreported matter in the street earlier that morning, around 8.30am.
