Banks and other major financial institutions were also found to have charged customers for financial advice when they knew it would not be given; to have forged documents; and to have repeatedly failed to verify customers’ living expenses before lending them money.

They also sold insurance to people they knew could not afford it, and lied to industry regulators, who have generally been too weak to do much about it, according to the findings and experts.

The cavalier behavior, experts say, is a byproduct of the dominance of Australia’s biggest banks.

Australia established a policy of prioritizing the country’s four largest homegrown banks with a so-called four pillars policy, which was instituted in 1990 to prevent any merger between Australia’s major banks: National Australia Bank; the Commonwealth Bank, which was owned by the government until 1996; Australia and New Zealand Banking Group, otherwise known as ANZ; and Westpac.

The banking business evolved with all four growing together. They operated with a heavy reliance on mortgages and on neighborhood branches, experts say, making it harder for international players to break in.

Regulators have long complained about lacking the resources to police the banks, even as they grew and developed a vast array of products that were often hard to differentiate or understand.

“There is evidence that they have sustained prices above competitive levels, offered inferior quality products to some groups of customers (particularly those customers unlikely to change providers), subsumed much of the broker industry and taken action that would inhibit the expansion of smaller competitors in some markets,” the report said. “All are indicators of the use of market power to the detriment of consumers.”