At the time of his death Moko was under the care of Tania Shailer who, with her partner David Haerewa, pleaded guilty to manslaughter after murder charges were dropped last month.
The worker was working for the Maori Women's Refuge which helped Tania find a home in Taupo to escape a violent past in 2013 and continued to work with Tania in 2015.
She denies ever being told about the abuse but raised concerns with Child Youth and Family that Tania wasn't coping with her own four children as well as caring for Moko and his sister.
"I felt I had left it in the right hands. I had taken it to CYF," she said.
CYF social workers, who dealt with the children's care, have not been publicly named.
The full interview is on Native Affairs tonight at 8pm on Maori Television.