Dual Passport
My parents are going from Denmark to Saudi for Hajj, via Pakistani quota. Turkish Airlines with transit in Istanbul. They must bring both passports.
My question is this, for online check-in which passport should be used? If Danish passport is used, would Turkish Airlines check if we have a valid Hajj visa in Denmark or Istanbul airport?
Same question during transit, when showing the passport before boarding, should it be Danish or Pakistani passport?