A high-ranking member of Canada's military is facing jail time and a reduced rank after pleading guilty to disgraceful conduct as a result of voyeurism at a court martial on Tuesday.

Master Warrant Officer Mardie Reyes, who was Sergeant-Major of the Denison Armoury and acted as a chief disciplinarian and counsellor to his subordinates, admitted to secretly recording bathroom video of female colleagues multiple times.

A courtroom packed with uniformed soldiers, Reyes's peers, heard that he targeted a female subordinate whom he was mentoring.

The victims' identities are protected by a publication ban.

Reyes installed hidden camera to spy on female corporal

He knew the schedule of the subordinate — a corporal — and would install and remove a hidden phone camera just before and after she used the bathroom to change.

An investigation found 15 recordings of the corporal at the Denison Armoury taken between August 2012 and January 2013 on Reyes's cellphone, MacBook and hard drive. He also had three videos, taken at the Moss Park Armoury during May 2012, featuring four other members of the military.

The military probe began after a captain found the hidden iPhone while using the bathroom.

The prosecutor, Maj. Chavi Walsh, described the phone as being concealed in a white case and taped to the white drainage pipes facing the toilet.

In a victim-impact statement, the captain — who served in Afghanistan — described her fear at the moment she realized she was being videotaped in the bathroom.

"I never thought that I would feel the same fear in a secure military establishment that I felt in a combat zone," she wrote.

The court martial also heard a victim-impact statement from the targeted corporal.

'Exposed and vulnerable'

She described her trouble sleeping, her constant worry that the videos were shared and her wariness to be alone with male colleagues.

"[Reyes] decided he had the right to film me when I was exposed and vulnerable," she wrote.

Both victims were present in the room to hear Reyes apologize before the judge. He said he would be seeking professional and medical help to understand what led to his behaviour.

In a joint submission, both the prosecution and civilian defence lawyer requested five months' imprisonment and a reduced ranking.

The judge was asked to consider Reyes's long and distinguished record of service. He joined the Canadian Forces just three years after moving to Canada from the Philippines and served for 26 years. He was deployed twice to Afghanistan and also formed part of the Canadian Forces response to Typhoon Haiyan in the Philippines.

Officials say the reduced rank is more of a ceremonial punitive gesture, as it is highly unlikely that Reyes will be allowed to remain in the military after his sentencing.

Reyes's lawyer asked the judge to delay sentencing for "a week or two" as his client organized his affairs — including finding extra help for his wife's business in Kingston and to arrange an alternative for his 17-year-old step-daughter who attends high school in Toronto.

The judge conceded one day. Reyes will be sentenced Wednesday morning.