Thanks for replies.
Clubman, my understanding is that the state licenses various fund managers or product providers who invest the money according to the regulations set down, but all the money is for the employees' use towards retirement benefits. Both Employees and Employers (can) contribute. Perhaps it's a bit like PRSAs here, but I think it's compulsory over there. However, the government can change the rules on investments, which is what they did a few years back!
My main question is really around the transferability. F. Kruger, thanks for reply. Do you know where I can get more detail on this as my friend is being told by a salesman in Argentina that it can be transferred ("for you special price", no doubt....). Also, what happens the money if he can't transfer it? Does it sit there unclaimed? If he returns to Argentina (to retire, say) can he claim it then, and is that the only way he can get at it now or in the future (based on current rules)?