Got the same guy, he called me and left a message.  Its a scam that has been going around don't listen to that iben alsharmouta.

The same "IRS" guy. He has left the same message asking to call back 206-436-4821. The phone # he was calling from is 206-414-4646.

Apparently this is still going on. I just got a voice mail from these guys. Heavy accent, very difficult to understand, mumbling something about me owing money to (undecipherable). They left a callback number of 206-436-4821. When you call that number, you will reach their "Internal Revenue Service Department". Ten minutes after I called them from a number different than the one where I got the VM, they called me back.
Scam !!!

I received a call from this number today - caller left voicemail at 4:30pm.  Male caller with a very heavy accent (sounds Indian or similar) identified himself in a message as "Jackie Parker from IRS, the Internal Revenue Service" - very difficult to understand due to background noise.  The caller said that he was calling about "an allegation that was charged on you," and requested a call back to this number.  Caller ID shows that the call came from 206-414-4646.  I reported this to the actual IRS at http://www.treasury.gov/tigta/contact_report_scam.shtml and will also call the report in during business hours.  

I phoned this number and found an outgoing voicemail message left by a man with a similar but less strong accent: "Thank you for calling Internal Revenue Service Department... currently we're busy with other clients...".  Definitely a scam.

I got a call yesterday from this #. They said they are calling from IRS left a message that my address is under federal investigation. I called back but nobody answered. This is a scam