Amnesty uncovers $588m in underpaid super

Roughly 24,000 business owners have come forward to admit underpaying superannuation to their workers.

An amnesty scheme that wrapped up earlier this month has turned up $588 million in unpaid super.

About 393,000 employees will either have the money paid into their super funds or bank accounts if they are no longer working.

The amnesty covered the entire period dating to the introduction of compulsory super in 1992.

Employers were given a one-off opportunity to wipe the slate clean by coughing up unpaid superannuation guarantee contributions, plus 10 per cent interest for every year the money was overdue.

Those that came forward were not penalised.

Assistant Superannuation Minister Jane Hume said the amnesty was aimed at reuniting workers with money that was rightfully theirs.

"We know that in the past, calculating the super guarantee has been very complicated," Senator Hume told AAP on Monday.

"The superannuation amnesty prompted honest businesses to take a look back through their records and check they'd done the right thing by their employees."

Once the payments have been processed, the Australian Tax Office will shift its focus to employers who have not repaid the money or set up payment plans.

Severe penalties apply for superannuation underpayment.

The Association of Superannuation Funds of Australia said delays or non-payments of employee entitlements could have a significant impact on retirement savings.

"Sadly, too many individuals are missing out not only on their superannuation contributions, but the potential returns from having more money in their super account," ASFA deputy chief executive Glen McCrea said.

Meanwhile, another 42,000 people have applied for early access to their superannuation in the past week.

About 24,000 people were applying for the first time and 18,000 were repeat applications.

At least 3.2 million people have now dipped into their retirement savings, with 1.3 million withdrawing money more than once.

More than $33.3 billion has been paid out since the scheme started in April, including $340 million in the past week.

The average payment is roughly $8000.

Former Labor treasurer Wayne Swan is a fierce critic of the early super release scheme.

He has also warned the coalition against deferring a legislated rise to the superannuation guarantee, which is due to take place next year.

"To effectively shackle and white-ant the national savings pool that drove us through the GFC would be the biggest economic mistake in 100 years," he wrote in The New Daily.