I just received the same call when i called back the guy acted as if he was an investigator and ask for my case # i told him i had no case number and why did they call me he got quiet and i said this must be a scam and he hung up.
got two voicemails from this number. I called back the second one and pulled up the phone number on my laptop as I was talking to the very heavliy accented indian lady. she said it was in regards to my back taxes which I have none and asked how i wanted to pay them. I told her I did not have any back taxes and was reading the IRS press release and realized this was a scam. I said it out loud and she hung up on me!!!!!!