yes fpj does not have a single filipino blood in him however he is still a natural born filipino and a filipino citizen. his citizenship was already resolved by the supreme court of the philippines. here is a portion of the said decision....
"(3) In ascertaining, in G.R. No. 161824, whether grave abuse of discretion has been committed by the COMELEC, it is necessary to take on the matter of whether or not respondent FPJ is a natural-born citizen, which, in turn, depended on whether or not the father of respondent, Allan F. Poe, would have himself been a Filipino citizen and, in the affirmative, whether or not the alleged illegitimacy of respondent prevents him from taking after the Filipino citizenship of his putative father. Any conclusion on the Filipino citizenship of Lorenzo Pou could only be drawn from the presumption that having died in 1954 at 84 years old, Lorenzo would have been born sometime in the year 1870, when the Philippines was under Spanish rule, and that San Carlos, Pangasinan, his place of residence upon his death in 1954, in the absence of any other evidence, could have well been his place of residence before death, such that Lorenzo Pou would have benefited from the “en masse Filipinization” that the Philippine Bill had effected in 1902. That citizenship (of Lorenzo Pou), if acquired, would thereby extend to his son, Allan F. Poe, father of respondent FPJ. The 1935 Constitution, during which regime respondent FPJ has seen first light, confers citizenship to all persons whose fathers are Filipino citizens regardless of whether such children are legitimate or illegitimate."
anyway for those who want to read the full text:
http://www.supremecourt.gov.ph/jurispruden...2004/161434.htm