I too received the same exact message from David Gray as did Ohio L!! EXACT SAME WORDS AND THREATS.
The message was left on my voicemail. I consider the message left on the voice mail to call back....or else!!! as a threat.
I feel very sorry for people who got scammed by this criminal organization. David Gray is a scam artist. He also had an
accent of some kind.

This is the message that he left. "Hi, My name is David gray, and this message is intended to contact you regarding an enforcement action executed by the United States treasury intending you're serious attention ignoring this will be an intentional second attempt to avoid initial appearance before a magistrate judge or a grand Julie for a federal criminal offense my number is 551-497-4103. I repeat It's 551-497-4103. I advise you to cooperate with us and help us to help you thank you". He's obviously a scammer. He called and left this message 5 times today. All within a 2 hour time span.

Google IRS phone scams and see type it in online this is a call center in Pakistan spoofing number saying your going to jail a law suit final notice anything to make people nervous report to the cops or the real IRS us general 18003664484

Just listened to my answering machine & got the same David Gregg message  threatening me if I ignore this call from the IRS, but he wants me to cooperate and he will help me. Yeah, right! Jerk!!!

David Gregg or David Gray what ever he goes by gets around , left a threating IRS message and a phone number that is to many a sender the one he left me to call is 551 497 4103 just in case it a similar message to you I would not advise calling to call him a Jerk is an understatement.