North Wales Police will be probed by the Independent Police Complaints Commission (IPCC) on whether it took sufficient action on a list of paedophiles given to the force by Canadian authorities.
The IPCC last year launched an investigation into how Essex, North Wales and North Yorkshire police acted on information the Child Exploitation and Online Protection Centre (CEOP) had taken more than one year to pass on to them.
Toronto Police had sent the CEOP a list of suspected paedophiles in 2012 as part of its Project Spade but officials delayed sending them to regional forces for a further 16 months.
In November 2013, the CEOP sent North Wales Police (NWP) a spreadsheet containing details of 12 people who were named by Project Spade in Canada that sought to identify the buyers of videos containing images of naked children.
After checking the information, three more names were added to that list. Following the delay, North Wales Police then referred itself to the IPCC while the National Crime Agency - which swallowed the CEOP - also referred itself to the IPCC over its own delays.
The IPCC has now revealed the extent of its investigation into NWP. It will look at:
•whether NWP followed any force-wide or national policies and guidelines in their handling of the intelligence data;
•whether NWP took sufficient action on the intelligence received and updated the NCA/CEOP appropriately about their actions;
•who within NWP had ownership of the information and who was responsible for supervising that person; and
•what steps NWP have already taken to prevent any recurrence of this issue.
IPCC Commissioner for Wales, Jan Williams, said: "Any incidents of failures in dealing with intelligence relating to the safeguarding of children are naturally of major concern to the community and the IPCC will be undertaking an investigation to discover whether any failures occurred in the manner North Wales Police dealt with the information they received."