The way I see it the issue is whether the maternal grandparents should have primary custody or the natural father. Since the father never filed for custody he doesn't have custodial rights until a court orders it. That's why he can't get the police to help recover the child.

The court will now have to decide whether to award him or the grandparents custody. They will look at several factors to decide which way to go with that.

Lets not forget the twist to all of this is that the mother is absentee. That alone may be a deal breaker. We don't really know for sure as it stands neither party has actual custody of the child between the grandparent and the father.