Australian Banks Hold Insufficient Capital

Fears Australian banks ill-prepared for housing-induced crisis

"Murray is suggesting, as others are, that you need enough capital to be able to deal with adverse situations without having to rely on the government. That's clear but what is not clear is the amount of capital, the length of time and the types of risks banks can continue to take on their balance sheets," he said.

APRA and other regulators have allowed some banks to use internal models to set risk levels, resulting in further downward revisions in the size of their assets and the amount of capital they hold. Because mortgages have historically had low levels of defaults banks have been allowed to hold only thin slivers of capital against large mortgage portfolios, making home loans very profitable.

Mr Brunton said AMP's white paper, which was published initially in November last year and updated recently to factor in the potential impact of the Murray inquiry, explored one bank and found that because of risk-weights it held just $4 billion of capital against $400 billion of mortgage loans – a leverage ratio of about 100 times.