NZF Group is the latest finance firm under scrutiny from the Serious Fraud Office.
The company's subsidiary NZF Money, which mainly provided commercial and residential loans collapsed in July last year, owing $16.4 million to investors.
SFO general manager of financial markets and corporate fraud Simon McArley says NZF is being investigated over alleged related party loans.
He says the investigation that's followed relates to five or six transactions which have occurred between NZF Money and the parent company and or some of the directors and offices of the company.
Mr McArley says the SFO originally received a complaint from the trustee of NZF Money and the office has been assessing that, and it's also received complaints from other sources related to NZF Money.