The Investigations into the Food World Shooting is into its third stage, with police, already interviewing witnesses.
While the identities of the two Filipinos cannot be released at this stage, police say are yet to establish a motive.
The Food World shoot out, occurred on the evening of last Thursday.
Police said two security guards, both expatriates, were involved in an argument which had led to a gun battle.
Part of the CCTV Footage which captured the incident was uploaded on social media.
While Port Moresby police say, the video may not be used as evidence in court.
It is reported that one of Filipino men shot and killed the other.
Two Papua New Guinean children were injured in the crossfire.
The incident occurred inside the shopping centre.
The suspect is facing a wilful murder charge, and remains in police custody.
Police cannot release any further details of the investigation, but they say they are working closely with the Philippines Embassy.