The Commerce Commission says it is happy with a settlement reached with five companies that marketed the Credit SaILS financial products to investors.
Credit SaILS were highly complex debt securities which collapsed in 2008.
The commission says the debt securities were marketed in a misleading and deceptive manner by the companies that described them as "capital protected" - which people thought meant their initial investment was effectively guaranteed against loss.
The commission reached a $60 million settlement last year with the companies and on Thursday released details of its investigation.
Chairperson Mark Berry said the commission could have taken court action, but investors - many of them elderly - might have had to wait years for a result.
"Settlement was a good outcome for these investors, most of whom are retired and elderly folk. They were dependent on the income flow from these investments.
"Our settlement gives them certainty that in 2013 for those who elect to take up the offer, they will get returned to the level of 87 percent of their investment."
The Commerce Commission warned financial advisers to ensure that they don't mislead investors in the wake of the Credit SaILS investigation.
It said anyone who markets or sells financial products must ensure that all information conveyed to investors is accurate, up-front and in plain language.
The commission said Credit SaILS were marketed to average investors, despite their complexity, and sellers must target their product at appropriate buyers.
The companies involved did not admit liability and have rejected the commission's view.