Interior Secretary Jonvic Remulla said the lone fatality linked to the Sept. 21 anti-corruption riots in Manila was struck by a stray bullet fired from an unregistered gun.
Speaking at a La Salle Institute of Governance forum on Thursday, Remulla said police personnel had been instructed not to use firearms during the operation.
He said a SWAT unit had been deployed only as support and maintained that the fatal shot did not come from the Philippine National Police.
Remulla said investigators traced the weapon through its serial number and determined that it was a loose firearm.
Human rights group Karapatan earlier identified the victim as Eric Saber, a 35-year-old construction worker who was reportedly caught in the violence.
Karapatan said an autopsy found that Saber suffered a gunshot wound to the neck and called for a full investigation into his death.
Remulla did not directly confirm that the victim was Saber but said the shooting occurred about a kilometer from the police engagement line, where no officers were positioned.
He also claimed that most gun-related crimes involved unregistered weapons, adding that many of these were allegedly held by dismissed police or military personnel.
