As well as the stolen firearm, Mr Milne said police located other "items of interest" that appeared to have been taken in another, as yet unreported, burglary.
It was possible the owner did not realise the items were missing. Until police had had a chance to speak to Wason they would not say what the other items were.
Mr Milne said the owner of the property where the stolen firearm was found was unaware that the offender had hidden the gun at his house.
"I want to stress that the occupier of that address is not involved in this offending in any way at all," he said.
A 17-year-old female associate of Wason's had already been charged for her part in the burglary. She would appear in the Kaikohe District Court at a future date.