I didn't answer because it was an unfamiliar number. It left an automatic recorded message saying they were investigating tax fraud and to ring back immediately. I will be warning people.

I got a recorded message in an American accent saying they were from some Tax place asking me to call them back ASAP and it was a final warning. I tried calling the number back straight away but it rang out

I just got the same kind of dodgey phone call .. Saying he was from the ATO and I was being investigated for tax fraud!! I questioned him saying it sounded like a joke & he said if I thought it was a joke then wait half an hour and the Cops will be banging down my door, or I could fix it all right now over the phone!!
I said to him that I'll stay here and wait for the police to come! And hung up!
It's been hours now and still no cops on my door!

Just got this call, didn't answer, but they left a 101 message to call ATO and ask for Director of Prosicutions. I called back but the number was unavailable.

It was automated message saying they were from the ato or tax department to ring them back.
I did and a Indian accent said he was from the Tax department. I asked why do you keep calling me. He hung up. Tried ringing back but engaged.