This is a Pakistan or India based IRS scam. Do not fall for it. The IRS does not initiate any legal action via phone.
Read http://www.treasury.gov/tigta/press/press_tigta-2014-03.htm
As general background information, here are a few things you can do:
1) Report it to TIGTA under http://www.treasury.gov/tigta/contact_report_scam.shtml especially if you have become a victim (lost money, gave personal information etc.). You can also file a complaint with the Federal Trade Commission at ftc.gov/complaint (include “IRS Telephone Scam" in your complaint). This way you can also help the government establish specific fraud patterns.
2) Help kill their phone lines but not by calling them back directly (the number may be spoofed and repeat calls by you may - under exceptional circumstances - amount to harassment). The scammers use Voice over IP lines (e.g. magicJack (Ymax corporation)) to make it seem as if they are calling from the US. This is always against these companys' terms of service and can lead to immediate termination of their contract and blocking of their IP addresses for future attempts to register. Do a reverse look up of their telephone number (e.g. www.whitepages.com) to identify the Voice over IP provider and report it to the company and/or law enforcement (local police and/or state attorney general)
3) If you are really annoyed: call or write to your representative in Congress. As these scams happen all over the country maybe this will trigger a reaction and provide US law enforcement agencies with the political backing and the resources they need to work in India and Pakistan together with local authorities (it can happen, read: http://m.ndtv.com/article/india/ex-call-centr ... mmission-320427). A US task force has already been set up in Jamaica to nab scammers there (see http://www.ice.gov/doclib/news/library/reports/cornerstone/cornerstone7-1.pdf). You can use the following template for your letter (more powerful!) or email:
January 29, 2015
Today I thought that all of my troubles would be over, when I received a call about the government giving me a 9000 dollar grant. This call sounded legit. It was not!!!!! My husband and I are usually very careful with our information, because we have very little and we have a family to take care of. I am so angry because I almost fell for it, and these people are prying on people that are struggling to make ends meet. I hope they are caught soon. the numbers that called were 202-239-1128 and 202-738-4261 first I talked to a woman and then I talk to a man that said he worked with the US treasury. when he was as to verify his name he said David Williams. He also gave me his badge number as AB679345.