Since the caller tried to contact them via the Spanish Police when it is the Portugese police who are leading the hunt I doubt that it makes much difference where they are.
Clearly the "credible source" is not sure who to speak to but with close on ?1m in their personal "kitty" made up of donations and a further ?2m on offer from various media sources as reward for info leading to the safe recovery of the child every nutter in the world will be calling some police station or other.
I bet the Portugese Post Office are flooded out with letters from Nigerian Princesses.