I rec'd the same call and message to my voicemail today. The script is exactly as above "The very second you receive this message I need you or your (inaudible) attorney return the call. The issue at hand is extremely time sensitive My name is officer is Greg Williams and the hotline to my division is 647-247-0890. I repeat 647-247-0890. Now, don't try and disregard this message and do return the call. If you do not return the call, or I don't hear from your attorney either, the only thing I can do is wish you good luck as the situation unfolds on you. Goodbye and take care." ........ the "take care" part made me laugh out loud :-)
Got a call from this number and a recorded message saying it's from CRA, requested me to return the phone call to discuss something like tax related legal issue.