I'm glad I goggled it to! I received the same message yesterday, and Ive been stressing ever since. I don't know what made me google it but thank god it's a scam! Thank you for posting this!!!
Received same call several times from Nikki Johnson. I called them back knowing that it is a scam. The man who answered had a middle eastern accent and said I was being investigated for tax fraud. I told him that I was recording the conversation and he hung up.
Ditto to all the above. I got the call/recording today, called right back and the middle-eastern accented man said "your investigator" is out, call back Monday.
Scam.....
The IRS uses certified snail mail to make their first contact, I know because I've been through it.
Thanks all for sharing your feedback!