Australian regulators yesterday launched an inquiry into the collapse of Opes Prime, a margin lending and private-client broking firm forced into receivership with debts of more than A$1bn ($917m).

Australia and New Zealand Banking Group, a secured creditor owed about A$650m, said that it had appointed Deloitte as receivers to Opes after the discovery of what it claimed were "a number of cash and stock movement irregularities".