A woman who was accidentally emailed details of thousands of ACC claimants threatened to go public if ACC did not guarantee her benefit payments for two years, ACC says.
In a report to ACC Minister Judith Collins on Friday, ACC said the woman was accidentally sent a spreadsheet including the names of about 6752 clients and the date and outcome of their review with ACC, in August last year.
It identified 131 claims were being handled by the Sensitive Claims Unit, which deals with claims of a sexual abuse, but did not contain details of a person's claim.
ACC met with the woman after it was notified of the breach in December.
It asked her to return the information and destroy any copies.
The woman, a client of ACC, said she wanted to negotiate a guaranteed benefit payment for two years, ACC said in the report.
"She made threats that if her demands were not met she would not return the information and she would inform the media of the alleged privacy issue."
ACC said senior management and police should have been told given the alleged breach and presence of a threat.
ACC has been trying to contact everyone mentioned in the spreadsheet since the privacy breach was made public on Tuesday and is sending letters of apology.