James Gibbs pleaded guilty to all charges relating to the theft of around A$4.88m (£2.7m, $3.4m, €3m) and other ‘dishonesty offences while director of James Gibbs Investments.
He must serve a minimum of seven years before he will become eligible for parole.
In delivering the sentence, judge Boylan found that Gibbs had built a relationship of trust with his clients, and then repaid their trust by systematically stealing their life savings and spending their money for his own purposes.
He said Gibbs stole from the “easiest targets … who placed blind faith in him”.
Boylan also remarked that Gibbs’ behaviour was “despicable” and “cruel” and his offences involved a “gross breach of trust”.
The 10-year sentence reflected Boylan’s view that Gibbs’ actions fell at the higher end of the scale in terms of seriousness.
According to the Australian Securities and Investments Commission (Asic), Gibbs committed his crimes between August 2009 and July 2016.
At the time, he was trusted by his clients to operate their self-managed superannuation accounts and open new accounts.
In some cases, he was given almost complete control of his clients’ affairs, which enabled him to conduct unauthorised transactions.
Once in control, he went on to steal their funds.
The money was used for his own benefit, such as propping up his business, paying his personal credit card debt, paying himself and his staff a salary and also for gambling.
Between June 2012 and July 2016, Gibbs created and used false documents, including bank documents and member statements, to lie to his clients about the value of their investment portfolios to cover up his thefts.
“Clients need to be able to trust their financial advisers, and in this case, Mr Gibbs breached that trust,” said Asic commissioner Danielle Press.
“Asic’s investigation revealed that Mr Gibbs deliberately withheld information from clients to avoid detection.
“Financial advisers should always allow clients to access information about their own investments, and clients should be concerned if this is not occurring,” she added.