I tried calling back and got an answering machine

c\Caller acting as CRA Fraud Inspector  giving probably fake ID

Got the same CRA Fraud Inspector. It was very demanding.
They also called showing this number. Same story.
800-711-1800

This number has been calling the last few days, and left a robo call today.  Sounds very urgent.  Glad I looked it up first.

Just called, got a nasty man with an Indian accent who said he had an arrest warrant for me. When I asked him to tell me what I did wrong, he said I knew...I knew that I was a dirty "[***]".

I got a voice mail that said: "The issue at hand is extremely time-sensitive. So, before you face any legal consequence, call us at 613.686.1545. Your disregard to call us back will be considered a blatant refusal, and we wish you good luck in front off your situation..."
I feel that this is either a prank call, or phishing.