So far, more than 1.2 million people have applied to access their superannuation early as a buffer against the coronavirus economic downturn, for a total value of more than $10 billion.

But the process was temporarily suspended following concerns about fraud.

Assistant Treasurer Michael Sukkar said the Australian Taxation Office had identified a small number of third parties who could be susceptible to criminal activity and was working with them to improve security.

"Australians can have confidence in the security measures the ATO has in place to protect the integrity of the early release of superannuation scheme," Mr Sukkar said in a statement on Monday.

Last week, Australian Federal Police were concerned up to 150 people had lost $120,000 through identity theft.

One case involved a tax agent whose systems were hacked by cyber criminals, resulting in clients' personal details being stolen.

Mr Sukkar said on Monday that people should never share their MyGov details with anyone, including their tax agent.

He said the tax office would never send Australians a direct link to log on to their services.

NSW Liberal senator Andrew Bragg said it had been a successful scheme, with illegal access to super always a problem.

"I think it a good idea to have access regimes like this on a more permanent basis," Senator Bragg told the ABC on Monday.

"All the funds will be refunding people who've been defrauded and there's an AFP investigation into it so it's not going to be swept under the carpet."

Labor has raised concerns the early access scheme will undermine the nation's retirement savings.

Australian Associated Press