Children's commissioner Peter Clarke has criticised local authorities for their "disappointing and slow" response to recommendations in his damning Clywch Report.
Mr Clarke had given chief executives until March 23 to make an official response to his recommendations to councils on tightening up child protection procedures.
But 10 months after the revelations in his report following the John Owen sex scandal, Mr Clarke said he was "still chasing" replies from Welsh councils. And he said he was still dealing with dozens of complaints about child protection procedures within schools and local education authorities.
Education minister Jane Davidson is due to update Assembly members on progress on Clywch next week, and present a final report in June. Almost half of Wales's local authorities failed to meet the March deadline, although most have since submitted reports to the children's commissioner.
Mr Clarke said: "Just over half of local authorities made the March 23 deadline - that is disappointing. I have been generally happy with the co-operation from most of the parties involved since the publication of my report. However, I am surprised many local authorities did not meet my deadline."
One of Mr Clarke's key recommendations was that all councils should appoint a dedicated child protection worker for schools within six months of the Clywch Report's publication last June. To date, nine out of 22 have done so - although others may have assigned the responsibility to existing staff members.
Other recommendations included compiling a fully police-checked register of "chaperones" for children working as actors outside of school; identifying the nominated teacher and governor for child protection in each school and their training needs; and developing plans for training for all staff in direct contact with children.
Sioned Bowen, executive adviser to the Association of Directors of Education in Wales, insisted LEAs had made the commissioner's recommendations a "top priority with the deadline in mind".
She said: "The majority of Welsh councils are already fulfilling the requirements of the recommendations, and the remainder are working towards doing so."
A spokesperson for the Welsh Local Government Association said that most authorities had already fulfilled the majority of the children's comissioner's recommendations.
She added: "Local authorities in Wales have taken the Clywch report findings and recommendations very seriously. Since the report was published last year, all councils in Wales have been working in close partnership with the association, the Welsh Assembly government and other stakeholder groups to develop action plans aimed at achieving real improvements for the most vulnerable children in their communities."
Mr Clarke called for sweeping changes to child protection procedures within education after investigating the case of former drama teacher and TV writer John Owen.
Owen killed himself in 2001, the day before he was to face charges of committing sexual abuse against former pupils. He had resigned from Ysgol Gyfun Rhydfelen, Pontypridd, 10 years previously, after complaints from parents and pupils about simulated sex scenes and use of lurid material.