The Australian Taxation Office has revealed plans to adopt an app with a duress signal available to 20,000 staff and contractors in a move to improve their safety.

Tax officials would adopt the app voluntarily, letting their employers locate them indoors to within 10 metres using a system monitored internally, and by an external security firm. Bureaucrats could install it on wearable devices and receive push notifications, text messages and email through the duress system.

The ATO said it would cover employees working at locations remote from ATO sites, its bureaucrats in shopfronts, staff at higher risk investigating potential criminal activity, and those travelling within Australia and overseas for business.

No incidents of violence or increased risk for staff have attracted the ATO to a duress app, but a spokesman said its decision to adopt it followed changes that had improved the new technology and made it more cost-effective. It expects a quarter of its staff and contractors will use the app.

Workplace researcher and co-director at Monash University's Australian Consortium for Research in Employment and Work, Greg Bamber, warned the technology was a "double-edged sword" that had the potential to be misused by managers.

"There are other sides of the coin to be watched," he said.

Mobile panic buttons, adopted by employers in Europe, were the subject of reports at the British Academy of Management annual conference in Bristol, UK, during September that employers had used the technology to monitor staff movements.

"It's not all beer and skittles, having something like this," Professor Bamber said.

"There's huge potential for this to be used in an unethical way and this should be watched carefully."

A tax office spokesman said it wouldn't use the smartphone duress app to monitor staff movements, unless expressly requested by individual employees. It has told IT companies to comply with its privacy rules protecting staff's personal data, if they supply the app.

"The ATO considers a smartphone-based personal duress application could be an effective tool for employees to seek prompt advice and assistance when challenged with a security or first aid issue, particularly those staff working off-site or out of ordinary hours," the spokesman said.

The Community and Public Sector Union said its leaders inside the ATO supported mobile panic buttons for staff, given the agency used safeguards.

CPSU acting director Emma Groube said tax officials were sometimes targets of threats, aggression and intimidation.

"The tax office, and indeed all employers, should be doing everything possible to ensure the safety of workers," she said.

"We’ll be keeping a close eye on this tender to ensure the smartphone app can only be used for its intended purpose. The tax office must make absolutely sure that this app can’t be misused by unscrupulous managers or anyone else to spy on staff or steal their data."

Australian Services Union official Jeff Lapidos, representing ATO staff, was disappointed the agency asked companies to bid for the contract to supply the technology before consulting with staff, unions or its own health and safety committee.

"The ASU would be very concerned if this duress alarm system could monitor the whereabouts of staff. ATO employees are already heavily monitored, and we can see no justification for even more monitoring," he said.

The tech company supplying the app will have a year to introduce it to staff.