Threatening arrest if you don't return the call

Caller: Said they are the ATO

I work for an accounting firm and one of our clients received a call from this number and I called it back to see who would answer. The guy said it was the ATO Melbourne and I said sorry but I have called the wrong number. He replied "No you haven't as we have left a message on your phone" - this is untrue as we have had no messages from this number. They must say that to anyone that calls. I hung up - definitely a scam

Threatening arrest and lawsuit if you don't return the call - same as above

Scam - threatening arrest if you don't call them back