Assuming they married in Argentina & will divorce here, then the "bienes gananciales" rule applies.
Everything obtained after getting married (except for a "bien proprio" resold to purchase something, with proper proofs, etc.) should be split 50/50.
If they are separated since a certain time (separacion de hecho), then the assets purchased during the separation might be considered as "anomalos", hence they are "bienes proprios".
Those are not funny times (got ruined financially, emotionally, etc.).
Should be checked too if he can ask the divorce for a fault from her part.
Of course, a very good lawyer should be seen asap.