When Greg and Julie Lewis sold their farm in regional Victoria for $2.7 million, they wanted to hold onto that money for their children.

Their money ended up with Australia's fifth-largest financial institution, Macquarie Bank, where they dealt with various advisers.

But the couple was encouraged to make high-risk investments, including in a fledgling mining operation known as a "penny dreadful".

The couple said they have since lost nearly all their retirement savings, forcing Mr Lewis, who had been self-employed for decades, to drive trucks for a living.

"I never thought I'd be doing this at my age," Mr Lewis said.

"My wife reckons I've been working harder than I ever have, and I'm a 63-year-old."

Greg Lewis didn't think he'd be driving trucks for a living at his age. ( Jennifer Douglas )

Sophisticated investors?

A former Macquarie Bank adviser told the ABC that customers like Mr and Mrs Lewis were routinely classified as "sophisticated investors" by Macquarie Bank's wealth management division.

The legal term allows any bank to place a customer's money into potentially volatile share trades without having to explain in writing the reason why or potential consequences.

Mrs Lewis said she and her husband should not have been put in that category because they lacked the necessary financial knowledge.

"We were not sophisticated investors," she said.

"We had no idea about the share market or the industry when we sold our farm and gave them that money to look after us and our future."

The law states a sophisticated investor must earn more than $250,000 a year or have more than $2.5 million worth of net assets.

The couple met that definition because of the value of their 6,000 acre farm outside Swan Hill.

That means Macquarie Bank's classification was perfectly legal.

But the peak body representing financial planners said it is irresponsible for any bank to categorise inexperienced customers as sophisticated investors without explaining the risks.

Macquarie Bank chose not to follow ASIC's guidance. ( Sergio Dionisio: AAP Images )

"Just because you earn a high level of income doesn't mean you are an expert in understanding financial products," said Ben Marshan, Head of Policy at the Financial Planning Association.

It was not just Greg and Julie Lewis's savings on the line with Macquarie Bank, it was also their nest egg, held in a self-managed superannuation fund (SMSF).

A guidance note from the corporate regulator at the time advised banks when it was appropriate to classify people with a SMSF as sophisticated investors.

The Australian Securities and Investments Commission (ASIC) said that anyone with less than $10 million in their SMSF could not be placed into that category.

Mr Marshan said ASIC was helping to protect customers from receiving bad financial advice.

"There were no ifs, whats, or buts about who the client was and their state," he said.

But Macquarie Bank chose not to follow ASIC's guidance.

A former employee, who agreed to speak on condition of anonymity, remembers the reaction of advisers when they first learned they didn't have to apply this guidance.

"It was seen as a joyful moment when a new adviser had started under the expectation that industry standards would be enforced but they were told that a super fund can be treated as a (sophisticated investor) as well," he said.

"There was a moment of joy that crossed the new recruit's face and it'd say whoop-dee-doo, I can't believe the shackles are off."

Not 'a sure thing'

This approach meant Macquarie Bank was able to place Mr and Mrs Lewis into a high-risk trading category and claim almost $700,000 in fees, according to legal records.

It advised the couple to invest in an aspiring resources company called Cleveland Mining.

Cleveland Mining's share price had fallen 92 per cent from its peak, to just 7 cents ( ABC News: Eliza Borrello )

Mrs Lewis says the company was sold to them as a sure thing, but after making an initial contribution, she became suspicious when their adviser repeatedly asked for more money.

"They said they had seen the mine, it's still in the early stages, won't be long and they will start drilling, this is going to go gangbusters, you need to get in on this," she said.

Through their adviser, the couple bought and sold shares in Cleveland Mining more than 30 times over a two-and-a-half-year period.

Nine of those trades were made using their super.

By September 2016, Cleveland Mining's share price had fallen 92 per cent from its peak, to just 7 cents.

"And those shares are obviously now in a trading halt, so you can't sell them anyway," Mrs Lewis said.

The company is now on the verge of collapse and operates out of a warehouse on the outskirts of Perth.

ASIC guidance scrapped

When ASIC discovered Macquarie Bank was potentially misclassifying customers it sought advice on the legal standing of its guidance.

The corporate regulator was subsequently told there was no legal basis for its advice and it was ultimately scrapped.

Mr Marshan said the decision has made investing riskier for customers with SMSFs.

"It significantly lowers the protection for self-managed super fund members and trustees," he said.

"Removing that interpretation has muddied the waters around which self-managed super funds can be considered sophisticated and which ones can't."

In response to questions, Macquarie Bank said legal opinion on ASIC's guidance differed at the time and it stressed that ASIC eventually withdrew its advice altogether.

Macquarie Bank said it stands by its interpretation of client classification and has always acted in the best interests of clients.

Compensation — for some

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 8 minutes 14 seconds 8 m Compensation process for Macquarie Bank clients who lost life savings 'a joke', say critics (November, 2015)

A week after ASIC withdrew its guidance note, Macquarie Bank announced a compensation scheme which promised to refund clients who received bad advice.

Macquarie Bank wrote to 189,000 former clients and received around 4,700 responses.

Only 263 clients, or 6 per cent of those who asked for a review of their file, were compensated.

Mr and Mrs Lewis had no success with the scheme, but representatives from Macquarie Bank recently organised a face-to-face meeting with the couple after the ABC began asking questions about their case.

Macquarie Bank said the Lewis's had not previously raised specific concerns.

Still, Mrs Lewis does not expect to see her money again and says she and her husband are considering joining other investors as part of a class action.

Macquarie Bank recently organised a meeting with Julie Lewis and her husband after the ABC began asking questions about their case. ( Jennifer Douglas )

"You think, how can someone be so irresponsible to let someone's whole life income or earnings go so fast?" she said.

Mrs Lewis said she is primarily concerned about her children missing out on an inheritance.

"As far as our kids go, they just say, 'Don't worry about it, it's gone', but we think we could have given you a bit of a start in life with some of that money," she said.

"They said, 'But we've got you'.

"Yeah, well, that's good, but this is a generational-built property that should have something for your kids, but, no, there isn't."