A Balclutha rental property is believed to be the first in South Otago to test positive for methamphetamine contamination, but commercial cleaners say it is just the tip of the iceberg.
Landlord Mark Cowan, of Dunedin, was "devastated'' by the news his rental property in Balclutha had been contaminated by a previous tenant who had smoked the class A drug, also known as P or Ice.
The level of contamination was such he had been told all the carpet and wall linings would need to be removed, and everything else would need to be decontaminated with special chemicals by cleaners wearing hazmat suits.
It was estimated the process would cost about $16,000, plus the cost of repainting and recarpeting the house, to meet the standards for re-renting and safe living.
Cowan was not sure if his insurance company would cover the cost.
He said he was also losing income because he was unable to rent the property until the cleaning was complete.
Grimewatch Cleaning owner Paul Mineur, of Balclutha, said meth contamination was becoming more prevalent in the South and he recommended landlords make sure their insurance policies covered it, because it was expensive to clean.
"A lot of insurance policies don't cover this sort of thing.
"You have to sit down with your insurance company and make sure you have all your boxes ticked.
"We've got a lot of drifters now. Balclutha used to be quite a quiet wee place, but you get a lot of strangers around town here now.
"It's a growing problem because it's cheaper to live here and we're getting a lot more people from the bigger cities in the north, migrating down south. They bring the problem with them, I'm afraid. There's also local ones who are into it, and they don't help.''
He believed the positive test was just the tip of the iceberg and there might be many other infected houses that had not yet been tested.
"It's very hard to tell if a house is infected because you can't really see it. There are telltale signs for landlords, like light bulbs missing all the time. But you can't smell it or see it.''
Mr Mineur said if a house was used to manufacture the drug, it could leave those living in it with cardiovascular, respiratory and dermal effects.
However, if it had been rented by someone who smoked methamphetamine regularly, the risk was considerably less.
Pure Services Ltd owner Dave Begg said one of the first symptoms some people noticed when they went into a severely contaminated house was their nose and eyes would itch, as with hay fever.
"It depends - some people are sensitive to chemicals, some people aren't. It depends on the individual.''
He said his company cleaned up to two methamphetamine-contaminated houses a month in Otago - mostly Dunedin houses contaminated by meth smokers.
To date, he had not seen the problem in South Otago, and was surprised to see it in Balclutha.
The Dunedin company cleans properties all over New Zealand and he said the bulk of the problem was in the North Island, where up to six houses per week were being decontaminated.