The Commerce Commission is investigating lending companies MyFi NZ and BHF Solutions, both of which have links to a payday lender recently expelled from doing business in New Zealand.
Pretty Penny recently reached a settlement with the commission, in which it agreed to pay back 21 customers and leave the country.
The commission was also aware of another loan company - Quickle NZ - with the same director as MyFi.
Debt management firm Debtfix co-founder Christine Liggins came across the link while helping a client manage their debt.
"We were asking MyFi to file a claim through the insolvency website and they said they'd filed it [but] sent us a screenshot that said Pretty Penny.
"We said 'hang on a minute... are you two connected?' They said 'no, no we're not connected' ... but it was the same person filing the claim and you look on the companies' register and you can see similar names appearing."
The director of MyFi and Quickle, Jack Martin, has the same listed Australian residential address as Quadsaa's (trading as Pretty Penny) director Mark Swanepoel.
Swanepoel was also a director of MyFi's holding company.
The director of BHF Solutions, Brenton Harrison, also registered the company with the same residential address as Martin and Swanepoel, which according to realestate.co.au is a 10-bedroom property worth almost $A2 million.
Harrison was also the director of the lending company Teleloans Ltd, which in 2015 came under Australian Securities and Investments Commission scrutiny. Teleloans is no longer a registered company in New Zealand.
The commission said it could not make further comment while its investigations were underway.
MyFi, BHF Solutions and Quickle have all been contacted for comment.