The Police Ombudsman has raised a number of "policing practice matters" with the PSNI in order to prevent further tragedies like the Greenvale Hotel deaths from occurring again.
Police Ombudsman Marie Anderson confirmed in a statement that investigators from her office have met the families of Lauren Bullock, Morgan Barnard, both 17, and 16-year-old Connor Currie, who all died on St Patrick's Day 2019 during a crush outside the hotel in Cookstown.
Mrs Anderson said investigators have briefed the families on a "broad range of enquiries" that have been conducted so far in the investigation, which was launched after a referral by the then Chief Constable George Hamilton in relation to the police response to the incident.
“My investigation is examining not only the manner of the police response to emergency calls but also the broader context in which these deaths occurred," she said.
The ombudsman said her investigators have examined data relating to telephone calls made to police by people at the Greenvale Hotel on the night of the tragedy and the movements of police in the area.
Police body worn video footage has been reviewed and investigators are examining police documentation and recordings of police radio communications relating to the incident.
Mrs Anderson confirmed that a total of seven police officers have been interviewed by her investigators – five in relation to the potential criminal offence of Misconduct in Public Office, and two about possible breaches of police procedures.
Mrs Anderson said investigators have already raised a number of policing practice matters with the PSNI to assist in preventing further such tragedies in Northern Ireland.
At the conclusion of the investigation the ombudsman will forward a file of evidence to the Public Prosecution Service for consideration.
The ombudsman will also be submitting a report to the Coroner's Office.
"All this takes time, but I have committed to continue to update the families and police officers involved about the process as our enquiries continue,” added Mrs Anderson.
The PSNI is continuing to carry out its own criminal investigation into the tragedy.
Hotel owner Michael McElhatton and a 40-year-old man, understood to be a member of the hotel's door staff, were arrested on suspicion of manslaughter last March before both they were later released on bail.
Mr McElhatton was questioned again over three days in June last year before being freed pending a report to the Public Prosecution Service.
The PSNI said eight other men have been interviewed under caution.
Seven of these have been reported to the Public Prosecution Service.