Called them back.  Gave them a fake name and telephone number got put on hold as it confused them.  The number appears to be a valid Canadian number with a 613 area code.  Cannot the telephone companies stop them using legitimate numbers?

Same prank, same name - Jonathan Knight..from CRA. Revenue Canada.

At about 9:30 am this Aug 19, 2015. I received  a phone call from the same number. A message was left in my VM and  when I call back the responding(so-called) officer replied and his name  was Michael John. This name  differs from the one left in my VM, but the voice  was from the same man, speaking with an Indian(asian) accent. I immediately reported this to the police a police.

Called and left a msg saying that if I ignore this msg that it would be a criminal offence. He said my tax return was suspisious.... then to call him call back. He did not leave a number, just his name and that he was from the CRA.The caller was identified as Officer Jonathan Knifght - CRA

I got a call from officer Michael John from Canada Revenue Agency threatening me with federal prosecution if I ignore this call and that is am the subject of investigation.

My caller said his name was Jonathan Knight.  Isn't he a singer??? Anyway, same threats, same east indian accent  I called the number with much hesitation because it sounded like a trick but the operATOR kept saying it could not go through.  Not sure how you can stop these people.