Voicemail message said I was guilty of tax evasion and tax fraud, and to call back or there would be criminal proceedings.

I received a scam call, pretending to be the ATO, and demanding that I call them back on this number, or I would face the legal consequences.

For more information on ATO scams see
https://www.ato.gov.au/General/Online-services/In-detail/Online-security/How-to-verify-or-report-a-scam/