Beware...This is a scam.  The Internal Revenue Service does not call.  They send letters.

Yes, they called and said a arrest warrant has been issued but left no name and just the phone number which is not in service. Scam!

I received a voicemail saying..."Before we move forward with the law suit and legal allegations, contact us as soon as possible."
I called the number twice and the call could not be connected.

Sheri, please don't call these people back. As Phyllis said (in an earlier post), "Beware...This is a scam.  The Internal Revenue Service does not call.  They send letters."  Use 800Notes to check the caller wherever possible. If you suspect spam or a scammer, block the number as appropriate. Any time some twit calls with an innuendo that you're about to be sued or arrested -- well, that's a sure-fire sign of a criminal. That's kinda like a sheriff calling a thief to say they're headed his way to arrest him. Riiiiiiiight.

Calling them back just assures that they DID reach a warm body and now they will escalate their calls to you, along with passing on this info to other scammers.

Thanks for the heads up...but don't worry, I called them back from my work phone...so a totally different number and the call didn't go through anyway. I just had to get confirmation for myself. I blocked the number from my cell phone.