Five search warrants have been executed in relation to the fraud, Australian Federal Police commissioner Reece Kershaw told a Senate inquiry on Thursday.

Bank accounts containing about $120,000 have been frozen.

No government systems have been hacked, Mr Kershaw said, but a third party provider has been.

The attack may relate to a tax agent.

The fraud relates to more than one superannuation provider.

"It is quite sophisticated," Mr Kershaw said.

Australians are able to access their super early to help them financially during the coronavirus pandemic.

Labor's financial services spokesman Stephen Jones says better protections need to be put into place, by bringing together all security agencies.

"We'd like to see frauds prevented before they occur," he told reporters in Canberra.

Australian Taxation Office boss Chris Jordan has urged the public to remain vigilant with their information.

"I would really wish to emphasise that people do keep personal information secure and private," he told the inquiry.

The fraud was first detected by Austrac and the ATO was alerted on April 30, before it was referred to the police a day later.

Industry Super Australia raised concerns with the government about the potential for fraudulent claims, and was told the ATO had checks to guard against fraud.

More than one million applications for early super have been approved, totalling about $9 billion.

Labor leader Anthony Albanese says Australians should never have been able to access their retirement savings early.

"We should be ensuring that superannuation is for people's retirement," he said.

"The government has to explain why it is that the mechanisms weren't in place to protect people's savings."

The Senate inquiry is looking into the government's response to the coronavirus pandemic.

Australian Associated Press