The Serious Fraud Office has confirmed it is investigating a US-based loan provider tied up with the B'On pyramid scheme and another SFO prosecution.
After an initial probe the SFO on Thursday said there was "reason to suspect that an investigation may disclose serious or complex fraud" involving the Brockstar Group.
Brockstar is headed by the Californian couple of self-styled "Sir" Brian Willis and his partner "supermodel" Snizhana Willis. Mr Willis denies any fraud and says he is the victim of a failed US contract.
Acting SFO chief executive Simon McArley said the agency was alerted to Brockstar during investigations into B'On Financial Services and another company Derivatek.
Last month, B'on Financial Services director Jacqui Bradley was more than sentenced to seven years' jail on 71 counts of fraud.
In both cases substantial sums had been paid as advanced fees in an attempt to secure loans from Brockstar, which never eventuated.
Mr McArley cautioned that the conduct may not have occurred in New Zealand, and would be outside the New Zealand jurisdiction.
Developer Rocky Cribb says he paid $US1.3 million to Brockstar and earlier this month, Fairfax reported B'On and Derivatek each paid $US1.3m to Brockstar on the promise of loan packages exceeding $20m.
In an email to NZ Newswire, Mr Willis said he had secured a US$200m contract with a hedge fund called GHZ Capital Funds to fund Brockstar's loan commitments.
However, Mr Willis said GHZ could not provide the funds which meant the B'On and Derivatek loans fell over, and he accused Mr Cribb of reneging on a follow up deal involving GHZ's bonds.
Mr Willis said he had laid a complaint with the SFO.