However, Unite union organiser Olive McRae says she is not satisfied with the police investigation and still suffers from neck pain.
The incident took place after Ms McRae joined a mass blockade of a motorway during TPP protests in Auckland in February.
She said the officer should have been charged with assault and wanted the findings of the "employment process" against him, and his name, to be made public to ensure such incidents were not repeated.
Police did not name the constable but said he used "unnecessary force" and breached police guidelines but did not assault Ms McRae.
This finding was backed by the Independent Police Conduct Authority (IPCA), which has now closed the file.
Details of the officer’s actions were included in a series of police reports obtained by Ms McRae under the Privacy Act and supplied to the Otago Daily Times.
A summary of the investigation said police found pulling hair did not constitute using more force than other techniques that were approved.
"However, it looked very bad when caught on camera and for this reason it was a breach of policy but not a criminal matter."
The full investigation report said TV footage of the incident showed he removed her from the road "grasping her pony tail and pulling her backwards".
It said the matter first came to police attention on the day of the protests, and several officers expressed concern about the officer’s actions.
"Other police staff present, including two sergeants, state that they directed [redacted] to change his behaviour, however none record that [redacted] acknowledged hearing or comprehending what they said."
The officer claimed wearing a full motorcycle helmet prevented him from hearing what other officers were telling him.
The officer told the investigator he felt the protesters were in a hazardous situation because of passing vehicles and they needed to move.He said he grasped Ms McRae by the hair and said she then "came almost effortlessly".
He was tasked with motorcade duties on the day and in his experience working in New Zealand and the United Kingdom had never been trained or served in public order or crowd control units.
Details about two other allegations against the officer, which were also upheld, were redacted from the full investigation report provided to Ms McRae.
The investigator recommended the case be addressed as misconduct but details about the results of an employment process against the officer were not included in the documents and police declined requests to provide them yesterday.
Ms McRae said the investigation was a "whitewash" and police should not be tasked with investigating themselves.
She was asked for documentation of her medical expenses relating to the incident but police declined her request to send them to an independent party.
"I don’t want to send personal, emotional information, to those who I perceive to be the abusers."
Ms McRae took issue with comments by Superintendent Richard Chambers, of Auckland, who, on the day of the protest, said police had demonstrated "outstanding professionalism" and pulling Ms McRae’s hair was a necessary action.
Police yesterday issued a statement defending the response to protesters "whose tactics were intent on disrupting the inner city".
"Police remain proud of the actions of their officers and note that no arrests were made."
Police declined to respond to specific questions about the incident.
