Australia's ANZ bank will be prosecuted over an alleged criminal cartel arrangement, the nation's consumer watchdog says.
Both the bank and a senior official were facing charges over the trading of its own shares, the Australian Competition and Consumer Commission (ACCC) said.
ANZ said it would defend the charges against the bank and its employee.
Australia's banking sector is currently the subject of a royal commission inquiry into widespread misconduct.
Two undisclosed companies and a "number of other individuals" were also expected to be charged by prosecutors, the ACCC said today.
"The charges will involve alleged cartel arrangements relating to trading in ANZ shares following an ANZ institutional share placement in August 2015," chairman Rod Sims said in a statement.
"It will be alleged that ANZ and the individuals were knowingly concerned in some or all of the conduct."
The consumer watchdog said it would not provide further details at this stage.
ANZ, one of Australia's so-called "big four" banks, said the charges related to a placement of 80.8 million shares.
It said regulators were investigating whether the bank should have stated that joint lead managers took up about 25.5 million shares of the placement, or 0.91% of total shares on issue at that time.
"We believe ANZ acted in accordance with the law in relation to the placement and on that basis the bank intends to defend both the company and our employee," ANZ chief risk officer Kevin Corbally said.
The deal was designed to satisfy regulatory requirements relating to capital at the time, it said.
Mr Corbally said the bank was co-operating fully with regulator the Australian Securities and Investments Commission.
Australia's banking and financial services sector has been rocked by a series of scandals over the last decade.
The royal commission inquiry, which began in February, has heard evidence of rampant industry misconduct.
Following the allegations, New Zealand's leading banks were told to prove they are not ripping off their customers like their Australian counterparts have been doing.
The Financial Markets Authority (FMA) and Reserve Bank spoke with the heads of New Zealand banks at the time seeking concrete evidence the same was not happening.
Much of New Zealand's financial sector is run by local offshoots of the same organisations now in the gun across the Tasman.
FMA chief executive Rob Everett said there was no evidence that what happened in Australia had occurred in New Zealand.