As more and more children come forward with accounts of abuse, we look at what the role the parents, police and expert child interviewers may have played.

To see more images and details about Peter Ellis and the series, vist the website here.

What's happening for the 3 to 5 year old children at the centre of the investigation, some of whom are put through hours of questioning by professionals feeling their way in a relatively new field?

How could happy, healthy, innocent kids come up with such distressing, and at times wildly fantastical stories? Memory specialists and child psychologists discuss the merits of children's testimony.

Go to this episode on rnz.co.nz for more details