Second PhD in Austria? When one already has a PhD from a university outside of Europe, could he apply for a second PhD in Austria?

I know that second PhD is not possible for example in UK. Is it the same for Austria? Is there anything against it?
Assuming that "apply for a PhD" means that you want to persue a second PhD in Austria; yes that's fine. You can get as many PhDs as you want, but you cannot use the same research for more than one PhD and you cannot do the same program (same university, field and title) twice as far as I know. 

If you are asking if you can use your research which was used for getting the PhD in a different country to get one in Austria the no, that's not allowed.