The financial regulator is in "a race against time" to identify more Ross Asset Management- type operations in light of the collapse of the suspected Ponzi scheme.
Financial Markets Authority (FMA) staff raided Ross' offices on The Terrace in late October after investors complained they could not get their money.
Receivers have been able to locate only about $11 million of the almost $450m customers believed were being managed on their behalf.
The company's assets, and those of founder and sole director David Ross, are subject to a High Court freezing order.
FMA chief executive Sean Hughes said that the law of probability suggested there would be more schemes like Ross operating in New Zealand.
"I have no doubt that there will be other schemes like this out there, and I guess it's a race against time for us to get there."
About 1200 financial advisers are authorised to offer discretionary investment management services. The FMA estimated there were about 10 advisers with the "fairly broad" mandate, similar to Ross' operation.
Staff would visit each of these with a "show me" approach, demanding records and proof they were legitimate, and investors may be spoken to. "Anybody who looks like a Ross-type organisation is getting early attention from us," Hughes said.
He expected staff involved in the investigations to report back by March or April.
Irregularities would probably lead to enforcement action. Two South Island advisers with a "similar style of operation" to Ross were likely to face enforcement action, possibly before Christmas, Hughes said.
The FMA accepted accountability for authorising Ross, but Hughes said it had no reason to not to do so. It had no intelligence suggesting there was a problem with the business, which was based in Morrison Kent House.
"On the first of May, 2011, when we came into existence, we had no knowledge of Mr Ross whatsoever," he said.
"Prior to us making a decision to authorise him in July of 2011, we didn't have a stack of intel [intelligence], which told us there was a red flag before we made an authorisation decision."
Hughes said the first time Ross came to its attention was when investors began contacting the FMA complaining that they could not get access to their money.
Hughes was aware of claims that the Securities Commission was contacted with concerns about Ross but these were not passed on to the FMA.
- The Dominion Post