The Nigerian email scams have been going on for decades. In fact even before the Internet and emailing becalmed commonplace these Nigerian. Today they are perpetrated almost entirely over the Internet via email. If you are not familiar the scam goes like this.
You'll be contacted by email from a person claiming to be a high ranking official in Nigeria. this person has access to a large sum of money and they need you to help them transfer the money out of the country. all you have to do is give them your bank account and routing number so they can make the transfer. They make ask for a small payment from you up front to cover expenses. Ultimately you'll never see any money, they will run off with the money you put up for them and they will use your banking information to print counterfeit checks to use in other scams.
If you are the victim of such a scam you are not alone so you should not feel too embarrassed. In fact tens of thousands of people have fallen victim to these scams. Unfortunately the FBI will not be able to help you track down your stolen funds back to Nigeria. There are just too many cases and not enough evidence to build a case.
But all is not lost. many times the "Nigerian scam" is not Nigerian at all. many times con artists located mostly in the USA and Israel have copied the Nigerian scam. In fact they will attempt to use a proxy IP to make it look as if the emails come from Nigeria when actually the crooks could be much closer to home and well within the reach of authorities.
The only way to determine if the trail does end in Nigeria or in the US is to hire a professional to trace the emails back to the sender and get an address to where the email are read and sent from. This is the only way you can recover the money that has been stolen from you. If the email can be traced to the US or to Israel you can get the attention of the legal system to recover your stolen funds.
There are private investigators located in the US that have the skills and tools to trace these scam emails right back to the sender and provide you with enough information to know if you can recover the stolen money or not. It is the only hope you have of ever recovering your stolen money.