Hong Kong may launch its own investigation into the Manila killings as the Philippines rejected a joint probe into the eight deaths.
Secretary for Security Ambrose Lee Siu-kwong said yesterday the Coroner's Court can instruct police to investigate the incident independently.
However, before the Philippines makes available the details of its own probe, Hong Kong can play only a limited role, skeptics said.
Undersecretary for Security Lai Tung-kwok said in Manila he had asked for a joint probe, but there was no reply from Philippine authorities.
Meanwhile, Philippine police confirmed yesterday that most of the victims died of gunshots. In revealing the preliminary results of a police inquiry, senior superintendent Agrimero Cruz said five of dead had gunshot wounds to their heads and necks.
Hijacker Rolando Mendoza, who was carrying an M16 automatic rifle and two pistols, fired at least 90 shots, the inquiry found. The autopsy on Mendoza showed eight bullet wounds.
Cruz said it was too early to determine, however, whether the victims were killed by Mendoza's firearms or police weapons.
The Legislative Council's security panel will discuss the incident today, with members saying the Hong Kong investigation will lack substance without cooperation from the other side.
Under current laws, a Coroner's Court can be set up with witnesses being called. Autopsies can also be done on the victims' bodies. But being unable to examine the coach, a full picture can hardly be established. Autopsies were only done on five victims because relatives of the remaining three refused to allow the bodies to be examined.
Two days after the rescue blunder, more information emerged as to what happened during the shooting. Survivors said that some hostages put up resistance as Mendoza started to go berserk .
Besides Ken Leung Kam-wing, the 58-year-old managing director who tried to stop the gunman, his daughter, Jessie Leung Song-yi, 14, died saving her brother Jason Leung Song-xue, 19.
In the last minutes of the standoff, Mendoza herded the hostages to the rear of the bus but kept tour guide Masa Tse Ting-chunn handcuffed at the front of the vehicle. As the first rounds of shots were fired, which killed Tse, several hostages tried to disarm Mendoza, according to reports. This was when the killer went berserk and shot randomly.
Joe Chan Kwok-chu was quoted in one report as saying that Mendoza then walked down the aisle and kept shooting. After endless rounds of gunfire, tear gas forced Mendoza to walk to the front of the bus, exposing himself to the marksmen, who killed him.
But according to Tracey Wong Cheuk-yiu, in another interview, Mendoza pointed at the air when he fired his first shot.
She said most of the shots were fired from the outside earlier.