Ubaydullah bin Utbah said: Sayyiduna Umar (may Allah be pleased with him) wrote to me regarding Fakiha bint Sam'an, who had passed away and had left behind a son of her real brother and a son of her paternal brother. Sayyiduna Umar (may Allah be pleased with him) wrote that the right of inheritance belongs to the elder (i.e., the son of the real brother).
Hadith Referenceسنن دارمي / من كتاب الفرائض / 3056