NT Police has admitted inappropriately accessing the private medical records of a public servant.

Former NT Department of Health worker Luke Horsfallwas with the department for 15 years until he was recently sacked - he claims unfairly.

Mr Horsfall worked out at a gym in Alice Springs available only to NT Government employees.

He said an accidental CC on an email chain revealed to him that the gym's committee members — comprised of senior police and public servants — openly discussed his private health issues after he went to the Alice Springs emergency department one morning.

“I came back to an email chain that had multiple police members,” he told the ABC.

“I was accidentally [copied] in on the email chain about my gym membership, and I was barred basically for being psychotic, schizophrenic, all sort of diagnoses that weren't my medical diagnoses.”

Reece Kershaw is currently the Northern Territory's Police Commissioner, but will soon move over to a new job as federal police chief.

Mr Kershaw has written a letter to Mr Horsfall in which concedes that an internal investigation by the Special References Unit found privacy had been breached.

“The investigation established a breach of your privacy and as such the complaint is sustained,” he wrote.

The Commissioner said the breach had been referred to the Police Standards Command, but gave no details on disciplinary action against the officers involved.

An email to Mr Horsfall from Detective Sergeant Wayne Newell from the Special References Unit suggests he “had identified possible criminal offences and submitted a brief of evidence to the Director of Public Prosecutions (DPP)”.

“The advice received from the DPP was that no criminal charges should be laid,” Detective Sergeant Newell wrote, according to the ABC.

“I have been advised that three members are subject to internal police disciplinary action.”

Mr Horsfall wants more than an apology.

“They need to be held to account,” he said.

NT Police will not say how the officers learned about Mr Horsfall's medical history, or whether the Department of Health leaked information about its own employee.

Mr Horsfall said the Central Australian Health Service (CAHS) - part of the NT Department of Health - illegally provided his information to the gym committee.

“Clinicians at the Alice Springs emergency department have divulged my private presentations, specifically relating to mental health where I've sought treatment in my private time,” he said.

“I've never had any mental health issues within work hours.”

Mr Horsfall said another letter he received from a senior manager included a string of dot points relating to his treatment at the hospital, allegedly proving management had seen his private medical files.

“Anyone who hears this story will be horrified, and rightly so,” said Community and Public Sector Union NT secretary Kay Densley.

“I think the NT Health Department and the police need to come clean about what's going on and how this happened.”