This number was the caller ID for what looks like an "ATO scam". Did not answer, but the "caller" left a computer-generated voice message claiming "This is Australian Taxation Office. As per a recent audit we identified incorrect tax filing" and "ATO send all the legal information to the courthouse to release the arrest warrant for you".

Have reported it to https://www.ato.gov.au/reportascam

Caller: 0403 214 994

Missed a phone call and automated message left said something about tax avoidance. I hung up and didn't listen to rest of message.