It's become clear that storage units are being used for more than just ordinary storage.
1 NEWS has witnessed the discovery of people living in a unit alongside stolen property, and the police have also confirmed it's identified and dismantled meth labs in storage facilities too.
The incident 1 NEWS filmed was in the Auckland suburb of New Lynn, and it took the man found inside over an hour to pack his bags, blankets and crockery into a van.
Police confirmed that man was later arrested and charged with burglary, as "a search warrant was carried out and a number of items of stolen property were recovered".
He was also charged with possession of cannabis.
MethMinder has carried out work detecting drug activity in units and its director Miles Stratford says while it's surprise hearing people may be living in these spaces, "the fact that things other than storage and personal possessions appear in storage units is not".
The facility manager of Storage King in the west Auckland suburb of Henderson, Grant Vivian, admits he's experienced someone who frequented their space too often, which quickly caught their attention.
It's currently expanding its facility and he says security is front of mind.
"It's a good business to be involved with but we've just got to be on top of our game, to have the checks and balances in place, which mean we avoid this kind of thing happening here," Mr Vivian told 1 NEWS.
Its monitoring includes cameras and a system requiring people to sign in and out when visiting.
"If someone's here for a particularly long period of time, we actually know they're here, so we monitor that very closely and if there's anything that seems out of the ordinary, we act on it," he said.
Mr Stratford told 1 NEWS he knows of instances where storage units have been used as a base for manufacturing methamphetamine.
But he says it's more commonly used for storing the chemicals and associated equipment.
"A storage unit is a pretty anonymous place you can do that so I imagine it's happening right across the country," Mr Stratford says.
"There are very few, if any storage unit operations, that are actively managing the risk because the pressure to do so is relatively low."
In a statement, police say they "will respond to reports of suspicious activity wherever it is happening".
"If you have any concerns or see anything suspicious, call police straight away."
Mr Stratford recommends people using storage units to be aware there's more that goes on than just storage of their personal items.
"Not everybody is as straight up and honest as they are and therefore they should be asking some good questions around the protocols in place," he says.