"The majority are investors with multiple properties who over-commit and may suffer some bad luck with rentals etc," he said.
"It's mainly in the lower price range properties. People over-committing and not having enough equity. They may have brought four to five years ago with high mortgages, then find they have a lack of cashflow."
He said the global financial crisis was partly to blame, with New Zealanders traditionally investing heavily in property. Mr Oppers said his firm had also dealt with a few commercial properties that had gone to mortgagee sales.
Rotorua Real Estate Institute spokesman Ian McDowell, of McDowell Professionals, said there were always a steady number of mortgagee sales in the city, with the occasional "spurt".
He said recently they were mainly investor type properties, rather than the average homeowning couple.
"They're having the pressure put on them by the banks," he said.
There is an upside for buyers - mortgagee sale houses have the potential to be snapped up at bargain prices.
McDowell Professionals director and auctioneer Phil Hereford said the banks endeavoured to get as much as possible from the market in a mortgagee sale.
"However the banks are the only sellers where the standard vendor warranties don't apply, the chattels are not included in the sale and the purchaser has to take the risk on the property from the date of the contract.
"Also the contract can be cancelled at any time prior to settlement by the bank. So, based on those factors the property should sell for below market value."
He added, though, that the degree of interest in a particular property could still drive the final sale price toward the perceived market value.
Terralink managing director Mike Donald said the numbers showed 2011 was not the year of economic recovery property owners had been hoping for, with some regions being hit harder than others. Nationally there were 2265 mortgagee sales in 2011, slightly down on 2010, with the Bay of Plenty one of a handful of regions to record a significant increase.
Mr Donald said nationally it was "more than likely" most sales were for family homes, not rentals.
"More mum-and-dad property owners are losing their homes. It's hard to claim things are getting better for ordinary Kiwis while this trend continues."