Custody of minors: Child's best interest will always prevail

Dear PAO:

Five years ago, Jean and I had a custody battle over my illegitimate grandson. Unfortunately, I lost because the law grants parental authority over an illegitimate child to the mother. My son, who was the child's father, has since passed away. Lately, I have heard that my grandson is being abused by his mother. My relatives are urging me to seek custody of my grandson. However, I am hesitant because I believe the decision on custody is final and absolute. Please guide me.