extending a visitors visa to remain in Paraguay.

Hello. My name is Tina and I live in the USA. This question is not about me, but rather our son. He left back in February on a 90-day visitors visa with the intention to stay and help build an "ecovillage." The man he is doing this with is a South African who is marketing himself and the project fraudulently. We know they have posted YouTube videos trying to gain "investors" to help pay. Their situation is this:

• They are building rammed earth buildings on someone else's land. They themselves own no land in Paraguay.
• They are luring people to Paraguay (so far, as much as we can tell, there are no takers) with the promise of a "new start" and a community for all.
• Their plan has always been to build a prototype so that people would give them money, and to simply stay and reapply for visas under "humanitarian" reasons. The South African started a "nonprofit" "humanitarian" organization in Belfast, but has only put false information on his website.
• His visitors visa expires this week. If he has not yet applied for a renewal, what penalties, if any, are there for overstaying?
• Also, who do we contact to report the fraud?