The Commerce Commission has offered immunity from prosecution to a financial markets participant as part of an investigation into possible manipulation of currency rates and influencing of benchmarks in foreign exchange markets.
The investigation started as a result of a "leniency application" under the commission's cartel policy, which protects those coming forward with information, the commission said.
According to its website, the consumer and markets watchdog operates a "cartel leniency policy" to encourage reporting of price collusion.
Banking industry insiders were in the dark over what the commission's foreign exchange investigation was about and inquiries directed at the Bankers Association and the Financial Markets Association drew blanks.
"At this stage we are unaware of any implications for our members around this particular issue," said Paul Atmore, chief executive of the Financial Markets Association, a professional body for wholesale banking and financial markets.