1. Petition; best interests of Indian child. Notwithstanding any provision of law to the contrary, whenever a final decree of adoption of an Indian child has been vacated or set aside or the adoptive parents voluntarily consent to the termination of their parental rights to the Indian child, a biological parent or prior Indian custodian may petition for return of custody and the court shall grant the petition unless there is a showing, in a proceeding subject to the provisions of section 3945, that the return of custody is not in the best interests of the Indian child.

2. Removal from foster care placement; procedure. Whenever an Indian child is removed from a foster care home or institution for the purpose of further foster care placement or preadoptive or adoptive placement, the placement must be in accordance with the provisions of this chapter, except for a case in which an Indian child is being returned to the parent or Indian custodian from whose custody the Indian child was originally removed.