The tax office is putting a halt to applications for early access to superannuation after instances of identity fraud were detected.

More than 1.2 million Australians have applied to withdraw nearly $10 billion from their super accounts during the coronavirus pandemic.

But federal police fear up to 150 people have lost $120,000 due to identity theft.

Assistant Treasurer Michael Sukkar said claims to early super would be frozen while the alleged frauds were investigated.

“We will undertake that process just to make sure there is nothing more that the ATO could do,” he told Sky News on Friday.

One case being investigated relates to a tax agent whose databases were hacked by cyber criminals.

Personal details of clients were exploited in the attack.

Home Affairs Minister Peter Dutton, who is responsible for various policing and intelligence agencies, said there had been no cyber intrusions within superannuation funds or the ATO.

“But we do have an instance where this one tax agent has had his system compromised and the personal details of some of those clients are being used in a fraudulent way,” Mr Dutton said.

Australian Federal Police Commissioner Reece Kershaw told the Senate select committee on COVID-19 on Thursday that an AFP cyber team was investigating an “intrusion into a third party” in relation to the government scheme.

He said the AFP launched the investigation after receiving a referral from the Australian Transaction Reports and Analysis Centre, which was tipped off by superannuation fund bodies.

Mr Kershaw said the attack was “quite sophisticated” and might be linked to organised crime or an overseas entity.

Labor’s financial services spokesman Stephen Jones described the decision to suspend the payouts as an “extraordinary turnaround”.

“Yesterday, government officials were grilled by the Senate select committee and they said yes, there’s 150 cases that have being investigated by the AFP. But there was no need for any changes to the scheme,” he said.

“Less than 24 hours later, the scheme has been suspended. So the question is this – what has the minister learnt in the last 24 hours? Is it more than 150 cases? We suspect it is.”

ATO Commissioner Chris Jordan said the tax office’s systems had not been compromised.

The early access to super scheme allows eligible superannuation members who are suffering financial hardship to withdraw $10,000 from their super by June 30, 2020, and another $10,000 by September 24, 2020.

More than one million Australians have applied to access money under the scheme. Super funds have already paid out more than $9 billion.

-with AAP