Mr Donald said the "big five" banks were increasingly forcing sales.
In 2009, he said, sales involving top-tier lenders amounted to 36 per cent of the total, but the figure this year was 55 per cent.
The number of forced sales in Northland rose 155 per cent, from 20 to 51, and Otago was up 153 per cent, from 15 to 38. Sale numbers in Hawkes Bay and Canterbury fell.
But Mr Donald said the overall picture remained bleak, and even record low interest rates were no help.
"If there's a silver lining anywhere in the figures, it's the drop in the proportion of individuals with a single property facing mortgagee sales, from 26 per cent in the first quarter of 2011 to 21 per cent this year," he said.
The president of the Auckland Property Investors Association, David Whitburn, said he knew of at least 40 landlords who had been bankrupted, and he did not see the situation improving.
"If these people were to go to a psychologist, they'd be classified as clinically depressed," he said.
"They've lost everything - their property investments, their homes and their self-esteem.
"I know far too many in this situation ... People like this have often had to get finance from second-tier lenders and are struggling to pay 11 to 14 per cent interest rates."
Relationships broke up and often family homes were lost, as landlords in retail or manufacturing had used their homes as collateral and banks were forcing sales to recover loans.
Mr Whitburn advises landlords to go easy on debt, keeping loan-to-value ratios to 65 per cent maximum.
Last year, Terralink recorded 2265 mortgagee sales, 169 fewer than the 2434 in 2010. Numbers began to rise during the second half of last year, and have remained high since.
The chief executive of realestate. co.nz, Alister Helm, said New Zealand homeowners had escaped the worst of the global financial crisis.
"We never suffered as they suffered in the US ... Their mortgagee situation got as bad as over 10 per cent of the properties being mortgagee or underwater, which is what they call repossession.
"That was the worst in the world, but it was a reflection of the whole property market."
Real Estate Institute chief executive Helen O'Sullivan said the rising number of mortgagee sales could be reflecting a stronger housing market.
"Banks might be taking the opportunity of buoyant prices to release stock that's been lurking for a while."