Asian accent demanding returning their call re: my tax fraud? Otherwise the local courts will prosecute me??

I have had several calls in the last 2 weeks leaving a message re tax fraud & tax evasion, with this as the call back number (odd Asian/American accent and I believe he said ITO). I work for an accounting firm and am in daily contact with the ATO. Do not return the call, this is a scam. The ATO never make phone calls of this nature and they never go to recovery mode without first corresponding with you by ordinary mail, not phone calls or emails.

Threatening legal action for "serious fraud" we've apparently committed. I'll be reporting this to police.

Just another scam

Pre recorded message about serious tax evasion charges.. Demanded I call back.