A police watchdog is to investigate after a child sex victim was named in a report submitted by the North Wales Police chief constable.
The girl was mistakenly named in Richard Brunstrom's report
The report mistakenly included information about the girl, whose attacker received a lengthy sentence.
But the girl's mother, who was delivered an apology by hand, says she is still not satisfied.
Now the Independent Police Complaints Commission (IPCC) is to investigate how the girl's identity was made public.
An IPCC investigation team will visit to North Wales Police HQ on Wednesday after the force referred the matter to them on Tuesday night.
IPCC Commissioner Tom Davies said the priority was the welfare of the victim concerned and that they had asked the force "to ensure it does everything it can to stop the victim's identity being published".
"However, this is a serious incident and I will ensure that a full and thorough investigation takes place. We will find out what happened and why it happened, " Mr Davies said.
The girl was named in Richard Brunstrom's regular update to police authority members even though under law victims of sex crimes are entitled to anonymity.
Everybody who received a copy of the report to Friday's meeting, including press and authority members have been asked to destroy it.
The force is also reviewing its procedures for checking reports.
The girl's mother told the BBC she felt angry and let down by the police. She said she would now take up the matter with the prime minister and her MP.
She said that if anyone else, a journalist for example, had revealed her daughter's name, that person would face prosecution for contempt of court.
"(The apology) doesn't mean much to me to be honest," she added. "The thing is whether they stop it happening again, it should not have happened in the first place."
Conservative MP for Clwyd West David Jones, said it was the "honourable thing" for the force to have referred the matter to the IPCC.
"It's important that everybody should be satisfied that the matter is fully investigated and treated with the seriousness it merits," he said.
"The whole purpose of the law is to protect vulnerable people who have undergone traumatic experiences.
"It's hard to see how an efficient police force could commit such a fundamental mistake."