The National Bureau of Investigation (NBI) will launch a probe into the cause of a recent fire at the Department of Public Works and Highways (DPWH) Region 4B MIMAROPA office, NBI director Jaime Santiago announced Thursday, stating that investigators are not ruling out arson.

The fire reportedly originated on the third floor of the building, which housed documents related to the Mindoro flood control project. Initial findings from the Bureau of Fire Protection (BFP) suggested the blaze may have been caused by an “octopus” electrical connection — the unsafe use of multiple extension cords and power strips.

“The fire reportedly started on the third floor due to improper and hazardous use of electrical cords and extension wires,” Santiago said, citing information from Fire Officer Capt. Bernard Soriano, who leads the local fire investigation team.

However, Santiago stressed that the NBI would not rule out the possibility of arson, particularly given the sensitive nature of the records stored in the building.

Public suspicion has grown over the incident, which occurred amid an ongoing investigation into alleged irregularities in the DPWH’s flood control projects.

“We do not rule out any possibility until the investigation is complete,” he said, adding that the NBI understands why people may find the timing unusual.

The NBI forensic team, in coordination with the BFP, was set to conduct a more thorough examination of the site Thursday. The area has been sealed and cordoned off as a potential crime scene.

Santiago said all occupants of the third floor would be called to give statements, and investigators would secure computers and other materials that may contain relevant information.

Claims that no flood control project documents were destroyed remain unverified pending the detailed probe, according to Santiago. The NBI and BFP have yet to release their final report on the fire’s cause.