Sydney: The justice minister, Michael Keenan, has expressed serious concern about the release of a tax office guide to hacking phones.

The ABC revealed on Wednesday that a tax office worker had published on LinkedIn a step-by-step guide to hacking phones.

The guide taught users how to access data, call records and text messages, including when phones were without Sim cards or battery power, the ABC reported. “Obviously we are very concerned about that,” Keenan said.

“But we do have very robust systems within the ATO [Australian Taxation Office] to detect that.”

The document suggests the ATO is hacking phones as part of its fraud investigations, although the agency requires a warrant or permission from the owner to do so. Asked whether this was a new strategy, Keenan said the tax office and other compliance agencies needed to “keep up” with the evolution of technology.

“I don’t really want to go into the ATO’s methodologies,” he said.

“But the ATO, like other compliance agencies in Australia, do need to keep up with the way technology evolves and they do need to exploit technology like other agencies do.”

The incident adds to a list of controversies plaguing the federal agency this year.

Public confidence in the ATO was damaged by the resignation of its deputy commissioner, Michael Cranston, over an alleged $144 million (Dh528 million) tax evasion scheme involving his son, Adam.

The deputy commissioner has been charged with using his position to help his son, but is not accused of direct involvement in the alleged fraud.

The tax commissioner, Chris Jordan, conceded in May that the allegations were likely to tarnish the ATO’s reputation.

The confidence of tax accountants and businesses in the agency has also been put at risk by a series of online system failures.

The outages, which began late last year, have caused lost productivity to the private sector and prompted calls for compensation.

The ATO has been contacted for comment.