Green Party co-leader Metiria Turei has weighed in on the debate, demanding CYF fronts up and tells the public whether it is undertaking mandatory checks of all family placements.
Mr Shanks said: "I can assure the public that our assessment process has been strengthened in the most recent years, with staff expected to do police checks if there are any concerns about family/whanau placements."
He said it became mandatory to do criminal checks earlier this year.
"(The woman) should never have gone to live with an uncle who was a convicted rapist and we are very sorry about what happened to her."