I got the same call. I guess I missed it because it came in September and I caught it while going through old voicemails. I knew it was total BS but I called back anyway just to see what they'd say. I got a voicemail asking me my situation so I could be moved to the top of the priority list. I hadn't even finished listening to his message before he called back. I told him I had received a message about a "Federal Investigation" and he told me he was sorry and that it was a mistake. I hope people don't actually fall for this stuff.
Yep, 2nd time in a month I got one. The beginning of the message is cut off and all I can hear was..."I was under investigation and to call back" at the stated number. I texted back some choice words (I guess if it's a land line, they won't get it, but it made me feel good :) Then I blocked the number. These people need to go out and work for a living instead of scaming others.