Hello,I'm Zoey and I'll be assisting you. Are you online now?
There is a real Nathan Sheets who is the undersecretary for the office of international affairs within the US Treasury. You can read about his appointment, which was back in 2014, on the official US Treasury website.
That said, if you heard from him the odds are astronomical that it is a scam. Like every other prominent official, his name is ***** ***** perpetrate many scams. Here is only one of them. I can find you many more.
So if "Nathan Sheets" has emailed or written to you, telling you that he has recovered money belonging to you, it is a well-known scam. The scammers are just phishing for your personal identifying information to commit identity theft and hoping to steal from you by getting you to pay thousands and thousands and thousands of dollars to collect so-called funds due you that don't really exist.
Don't fall for it. Report the scam to the FBI at IC3.gov and send no money!
Just checking in to see if you need more help or any clarification of my answer. If so, please reply here on this question thread.
You cannot reach me via email. That's why I did not respond to the email you said you sent in the second question you posted on this site. You replied to an auto-reply from JustAnswer and whatever you wrote is lost in cyberspace. You must reply right here on this question thread for me to receive and read what information you want me to have.
The US Treasury and Nathan Sheets have no jurisdiction over you whatever in Australia, and they could have no legitimate business with you at all. This is a well-known scam designed to get money from you. If you wish, you can upload a copy of the email you received to this question thread and I should be able to prove that to you.