Laura Gillespie has worked with the Financial Services Authority on investigations into allegedly fraudulent schemes.
She said that allegations of fraud were “not uncommon in tough economic times”.
She tells BBC Newsline: “When the money is rolling in, people tend not to ask questions but lean economic times certainly tend to reveal problems.”
Ms Gillespie said that investors needed to be alert to “tell-tale signs”.
“First, consistently steady returns – if your investment yields say, 3%, consistently over a period of years, there is so little variation that it might cause suspicion,” she said.
“Second, if the investment consistently outperforms funds of a similar nature, something may be awry.
“Like any fraud, the rule of thumb is simple: if it seems too good to be true, it may well be.”
The interview will be broadcast on BBC Newsline at 6.30pm.