External employment lawyer Peter MacDonald confirmed yesterday Mrs Cooper had taken action over her dismissal and her case would be investigated.
"She has lodged a claim ... which of course she is completely entitled to do." He declined to comment further.
Mr MacDonald was employed by the Ministry of Education after the Educational Review Office (ERO) found divisions in the communication structure of senior staff.
After a month and a-half and 13 visits to the school, Mr MacDonald and Mrs Cooper could not come to an agreement and the principal was asked to leave - which she did the next day in a move which shocked the school community.
Mrs Cooper could not be contacted to comment on her ERA claim yesterday.
A complaint to the ERA can take up to a few months to be resolved, depending on urgency, according to the ERA website.
A member of the ERA will investigate the case if both parties have previously tried mediation and the eventual decision is based on "merits of the matter and not technicalities".
Both parties will take part in meetings where issues are discussed and investigated by the ERA member present.
Deputy principal Grant Adolph has been appointed principal in the interim while the board of trustees, along with Mr MacDonald, search for the ideal candidate to lead the school by term two next year.
Parents of school pupils were invited last Tuesday to discuss any concerns they had over the abrupt departure of Mrs Cooper.
Mr MacDonald said at the time, the 80 parents who attended the meeting left somewhat satisfied and they could now move on.
However Mrs Cooper's claim to the ERA could now be a setback.
He plans to return to Queenstown from his Christchurch office sometime next week.
Board of trustees members could not be reached to comment.
