VANCOUVER -- A Vancouver police sergeant who entered into a relationship with a vulnerable subordinate has been fired after a disciplinary investigation found he engaged in "discreditable conduct."

Sgt. David Van Patten became romantically involved with Const. Nicole Chan while she was on stress leave from the department back in 2017. The 30-year-old constable took her own life in January 2019 amid an ongoing battle with mental health and depression.

The relationship eventually prompted an external Police Act investigation, which was carried out by the New Westminster Police Department and overseen by Chief Const. Dave Jones of the Metro Vancouver Transit Police.

This week, Chan's family was informed that the disciplinary investigation was complete, and that Van Patten was found to have committed three acts of discreditable conduct.

"Chief Officer Jones imposed penalties which included an order that Sergeant Van Patten be dismissed from the Vancouver Police Department," the Office of the Police Complaint Commissioner said in a news release Thursday.

The deceased's sister, Jenn Chan, told CTV News the outcome is just one step in the family's "ongoing efforts to get justice for Nicole."

"While we are satisfied that the correct decision was reached with the termination of Sgt. David Van Patten, we remain deeply concerned with the events leading to Nicole's death," she wrote in an email.

"More needs to be done to hold those who abused their power accountable and for Nicole's friends and family, this issue is far from resolved."

Because the OPCC process isn't open to the public, and the complainant is no longer alive, there are few details available about the allegations against Van Patten.

The deceased's family did provide CTV News with a journal entry written by Chan before she died. In it, she refers to the senior human resources officer handling her stress leave file – which CTV News has confirmed was Van Patten – and says she was "betrayed, coerced and taken advantage of by somebody whom I respected and looked up to."

"There was a huge imbalance of power and I was severely depressed," it reads. "I was honest with the department about my struggles and the person in power used this information to exploit and … to manipulate me."

Multiple calls from CTV News to Van Patten's phone went unanswered on Thursday.

Another of Chan's superior officers, Sgt. Greg McCullough, also entered into a relationship with the younger and more junior constable, and was previously found to have engaged in discreditable conduct.

An email obtained by CTV News last year revealed McCullough was given a 15-day suspension for "failing to disclose to his managers a relationship with Nicole" and for "entering into a relationship with Nicole knowing she was in a vulnerable state mentally and emotionally."

The sergeant has since retired from the force.

Chan reported both relationships to the Vancouver Police Department about a year before her death, which initially prompted an internal investigation. Her family has told CTV News as the months went on, she doubted anything would come of the matter.

"I think she always had in the back of her mind justice wouldn't be served – they'd just get a slap on the wrist, and that was a huge thing weighing on her," Jenn Chan said last year. "She felt hopeless about the whole situation."

In April 2018, the VPD forwarded the information it gathered on Van Patten to the Office of the Police Complaints Commissioner, which ordered the external Police Act investigation from the NWPD.

After determining the allegations appeared to be substantiated, Chief Jones ordered a disciplinary proceeding in December 2018. The proceeding was supposed to begin in February 2019, but was pushed back for further investigation.