Parent,s responsibilities viz a viz costs of child,s University Fees

past a certain age. I need to find out if, here in Spain, an estranged parent is held to be responsible for the costs of a child staying on a university past a certain age. In the absense of any consensual agreement for a parent to cover these costs does the law here in Spain necessitate that a parent be responsible to continue paying beyond say 18 yrs. of age? It has recently been suggested to me that even at the child,s age of 25 yrs. a parent continues to be held responsible. This seems to me to be totally wrong but I am keen to know the facts.
Any help gratefully received!