Although a slightly different case, they do have computerized cross references in place. My Filipino born-and-raised partner became a US citizen 20+ years ago. Recently he reclaimed his Phiippine citizenship, but never got a Phlippine passport. Last time he traveled from the US to Manila, he presented his US passport as he had done for two decades and the immigration agent demanded to see his Philippine citizenship papers since the computer flagged his US passport. They had no problem with his presenting US passport and they let him enter with no delay other than checking the Philippine paperwork, too.