Whenever an Indian child has been adopted and the relationship between the adoptive parent and the Indian child has been severed for any reason, a biological parent, guardian or prior Indian custodian may petition for return of custody, and there shall be a presumption that the Indian child shall be returned to the biological parent, guardian or prior Indian custodian, unless the return of custody is not in the best interests of the Indian child. The provisions of this section shall not be deemed to conflict with other provisions pertaining to return of custody in the Indian Family Protection Act.