There's a website called Global Property Guide that includes a discussion on rental income and taxes in Argentina. I tried to bring it up but it's not working at the moment, perhaps you could try a little later. He should be fearful as I believe what he is afraid is exactly what could happen, along with interest and penalties. He should seek some professional advice in Argentina. I wouldn't bury my head in the sand and hope for the best. Perhaps someone with rental property here will post. I suspect a lot of people who purchased property over the last few years are in the same boat.