Were these cash withdrawals? Three lump sums over $10,000 or under? Or just transfers of funds?
If it's cash, then amounts in excess of $10,000 dollars are automatically reported to the IRS. So...make sure they're aware of the transactions; they'll be VERY curious to know what happened to the money. ;)
Otherwise, I can think of a few ways to do the transaction so that he makes sure you CAN'T find out.
Which means I have to think about how to get around that...hmmm... tricky... Savas must think like an honest person... :)
Do you know anyone with Mexican relations you feel you can trust? The big problem with this sort of situation is getting someone out of country (In Mexico, in this case) who won't take advantage of you and just steal your money.
Maybe its time to legal advice.
There are two ways that an American can buy land in Mexico. Direct ownership and a real estate trust. The latter is used when the land is within 100km of the coastline or within 100km of the Mexican border. (This gets around a restriction in the Mexican constitution which says that only a Mexican national may own land in that area).
To be involved in a trust, you have to have a permit that you get from the Mexican Ministry of Foreign Affairs. The trustees that hold the property are typically a bank, so finding the permit, while it would not completely solve the problem,
Buying interior land directly would be much like the way it is done in the US, there would be a title deed. Chances are, it would be on file with the Mexican state where the property is (just like in the US).
You would probably have to find someone in Mexico who knows this stuff to track it down.