Suppose one has a clean criminal record, and takes up Portuguese residence. During the 5 years residence required for eligibility to gain citizenship, one comes under criminal investigation and is then convicted in one's country of origin, of grave and universally recognised crimes. What implications does this have upon one's path to Portuguese citizenship?
Without knowing what is to be understood by:
of grave and universally recognised crimes
no precise answer can be given (vague details lead to vague answers).
One reason for denial of an application is given in Portuguese Citizenship Act, Artigo 9 P
b) has committed a crime with a maximum penalty of imprisonment of more than three years according the Portuguese legislation;
Important is the maximum sentence possible, not the actual amount of the sentence.