En su propia web ellos mismos aclaran que no son un banco registrado en Nueva Zelanda. Dicho esto,deberias investigar un poco para saber donde metes tu dinero:
It is a New Zealand Financial Services Company, they were popular a few years back as they could basically act like a bank (take deposits, lend etc.) as long as they didn't use the word "bank" anywhere to describe themselves.
They have fallen out of favour as regulations have tightened, most banks will no longer deal with them due to the huge regulatory risks.
These guys look like they have saddled-up with a single borrower of the funds (MASSIVE concentration risk right there) in UK property development (another substantial risk). It also seems that they have found a bank willing to offer correspondent accounts, which wouldn't have been simple. I suspect that the correspondent bank is located somewhere like Ukraine, Armenia or possibly Belarus. That is a question that you would want answered.
Is it a Ponzi scheme? Possibly, but I doubt it. Is it paying anywhere near enough interest to commensurate for the risk of the investment? Hell no! I have a friend who raises mezzanine financing for property development and his investors get close to 20% pa for the risk involved. The risks are not small and should not even be compared to a bank deposit (which is how these guys are selling it).