SYDNEY - Australian public servants have been told to report colleagues who take long lunches or waste time at work, local media reported.

The Australian Taxation Office sent out a memo to 20,000 staff in December urging them to be aware of their workmates' behaviours, according to BBC.

"You might have seen it before," the memo said.

"A colleague makes a habit of taking long lunches; or regularly leaves early; or spends the first hour at work eating breakfast and reading the paper... or all of the above."

It added: "Maybe they just lose track of time, or are careless rather than acting deliberately. Maybe there are indeed reasonable explanations.

"Or perhaps your suspicions are correct and they're simply not recording their working hours appropriately."

It said that staff had an obligation to report possible fraud to investigators, who would check if that long lunch break was authorised.

It noted that staff may feel uncomfortable reporting on their colleagues, and offered assurances their reports would be treated as confidential, ABC News reported.

Critics have denounced the policy as harmful to workplace culture.

"You're jealous because someone else is away from work... and because you don't like it, you dob them in," Australian Services Union secretary Jeff Lapidos told ABC News.

Associate Prof Angela Knox, a workplace expert from the University of Sydney, said the policy created a hostile environment.

"This Big Brother-style surveillance is very worrying," she told the BBC.

"If I were an employee I would be thinking that the workplace doesn't trust me and that perhaps I should rethink the trust I have put into the workplace."

She said it would inevitably lead to higher turnover rates among staff and drops in motivation and productivity.

In a statement, the tax office said the majority of its workers had complied with its expectations.