FIFA has already conducted an enquiry on this and has ruled that Byron Castillo is an Ecuadorian citizen. And as far as I know, whether he was born in Colombia or Ecuador should not matter, in case his Ecuadorian nationality is unchallenged. Naturalized citizens are allowed to participate in the FIFA world cup. I know that Chile football association is trying hard to get Ecuador disqualified. They should be ashamed of themselves. First they can't secure a qualification spot from the CONMEBOL. And now they are trying to get one of the qualified teams suspended.