Sibur was allegedly mauled first before he was thrown into the river, according to earlier reports.
"The case is still under follow-up investigation and we are hoping for positive results in the coming days," said Superintendent Wilson Santos, the town's chief of police.
As of Sunday afternoon, the Masantol police have yet to identify the suspects in the killing since there was no lead yet in their investigation.
Santos also said they already invited people from around the area and from nearby places in order to shed light to the victim's death.
He said there were still no witnesses who are volunteering to give their statements.
Vice Mayor Bajun Lacap meantime said during the interment of the victim last Sunday, he is keeping his fingers crossed that the case will be solved soon.
The Municipal Government is also calling on concerned citizens to surface and become possible witnesses to speed up the resolution of the case.
