Got this call and seriously was harassed and interrogated told there was a warrant for my arrest and when they told me I could pay outstanding balance I told them, "This is a Scam and hung up" When I later tried to call them back they cussed me out....I'm so flipping mad. Actually got called twice in one day!
 Mar 04th, 2017
They will tell you not to tell anyone, nor disconnect the phone nor put it on mute. They will ask you to go to Walmart and get a tax card which does not exist ... they will threaten you with a warrant for your arrest as the IRS is supposedly filling a lawsuit against you.
Fake badge ids and american names are used.
Here are my note from these fake scammers:

Officer Sharon Brown - GS2190 -

Says IRS says lawsuit against me from 2011-2015 - miscalculations errors

Section 7201 - Amount is outstanding $2470

tax pay card - at walmart. When you get there there is no such card,so they ask you to buy gift cards and give them the numbers on the spot. Remember, at this time, they are still with you on the phone. They say you will enter the code after on the irs website. A gift card code, c'mon!!
After you say no to them the spoof a number from your local police department and pretend to be a police officer who just got the warrant for your arrest from the IRS. Officer Marcus in my case.

CALL THE FBI and get INSTRUCTIONS ON HOW OT FILE A CASE if it happens to you!!! By the way, Indian accent all over. They are not Americans.
 Feb 28th, 2017
fake scammers impersonating the IRS. Dow fall for it.
 Feb 28th, 2017
This was left on my voicemail!

“My name is Ofc. Marcus Brown and I a.m. calling from criminal investigation division _⁠_⁠_⁠_⁠_⁠_ _ are at the matter at hand is extremely time sensitive and urgent as after August we found that there was a fraud and misconduct on your tax which you are hiding from the federal government this needs to be rectified immediately so do return the call as soon as you receive the message the number is 202-580-8464 I repeat again 202-580-8464 thank you…”

I called back, they confirmed my phone number, said they couldn't help me, and hung up.
 Feb 28th, 2017