She said few of the taskforce's recommendations had been adopted and the sector's ability to prevent and deal with the country's high level of sexual violence had been diminished by funding cuts.
Sexual violence against children happened on a daily basis, affecting an estimated one in four girls and one in eight boys under the age of 16, she said.
"Although rarely by a stranger, every year a few of these thousands of children throughout the country will experience one-off brutal incidents similar to the one reported in Turangi.
"Others will experience regular sexual violations that may be repeated over months or even years.''
Sexual crime was also by far the most costly crime per incident, she said.
"Treasury estimated that sexual violence directly cost the economy $1.2 billion in 2003-2004, and the new cost now could be as high as $7.5 billion per year.''
A spokeswoman for Mr Key said Dr McGregor's letter would be replied to in due course - Jamie Morton
