New figures show a record drop in new home loans, falling 15 per cent overall in the September quarter.
Investor loans fell much faster at 31 per cent, compared to 5 per cent for owner-occupiers.
Housing Minister Clare O'Neil welcomed the fact that home owners were faring better than investors.
The number of new home loans plummeted through the middle of this year, especially for property investors, as rate hikes and tax changes cooled the housing market.
The total number of loans fell 15 per cent, and their total value dropped 16 per cent from June to September, according to figures from the Australian Bureau of Statistics.
New loans for investors fell by 31 per cent and by 5 per cent for those buying for themselves.
Both the overall and investor drop broke official records.
Mish Tan, the head of finance statistics at the bureau, said the data suggested investors were being deterred not just by high rates but by "tax changes and expectations of lower house prices".
Conditions in the housing market were weak before the May budget, when the federal government unveiled plans to curb property investor tax breaks, but have deteriorated markedly since that time and spread beyond Melbourne and Sydney to other capitals.
