They visited the Maunu Rd address at 10am on Thursday and, while there, noticed some clothing that had allegedly been stolen in the shoplifting incident.
Ms Phillips said police then entered the house and, while inside, located some paraphernalia related to methamphetamine, a pistol, some ammunition, several thousand dollars in cash, and a quantity of unknown pills. Officers used the Search and Surveillance Act, 2012, to enter the property.
Two people were arrested - a man aged 36 and a woman aged 28 - and they were jointly charged with unlawful possession of a pistol, unlawful possession of ammunition, possession of utensils for the use of methamphetamine. The woman was also charged with possession of cannabis.
Ms Phillips said the arrests demonstrated that thorough inquiries of what might seem a minor incident could lead to the discovery of something more significant.
"Our staff did some great work in firstly tracking down an offender in relation to the shoplifting offence and then deciding that something didn't add up and going further with their inquiries," she said.
The man and woman arrested in relation to the alleged drug and firearm offending appeared in Whangarei District Court yesterday and were remanded in custody to reappear in court on Monday.