I also received phone calls from 203-485-2105 and 203-485-2068 and name ID showed as Capit Greenwich. One lady said to me that there would be a warrant for my arrest and she called my home several times each day and I don't know what she really wanted from me. I called the number back and I heard a Indian guy's message. It looks like it's the same group of people. Thank you for reporting it here so that I know it's a IRS Scam.
I received a call ftom this man too on June 3rd 2015. But first it was a lady she said her name was Anthia Welcon. Both have Indian accent. It was also about the IRS and tax evasion, and asked me for 3800$.
The phone no. was :
872-213-9153
And I forget to say they called me again on June 10th 2015. In both phone call there was a background sounds of people talking look like they are in a busy company or they only put that sounds to give it more spices and make it look real.
Hopefully I was helpfull.
Thank you all