The stabbing incident at the New Bilibid Prison (NBP) last September 28 was not a riot but a premeditated move to kill high-profile inmate Jaybee Sebastian, an investigation by the Criminal Investigation Detection Group (CIDG) revealed.

This was reported in a hearing at the House of Representatives justice committee on Wednesday. Convicted drug trafficker Tony Co was killed while three, including Sebastian, were injured.

"No riot or tumultuous fray occurred. What transpired was two separate and simultaneous stabbing incidents inside the makeshift room of Tony Co and at the mess hall area," said Superintendent Francisco Ebreo of the CIDG in the hearing.

"The incidents were triggered by separate causes and there was no showing that they acted together in a disruptive and tumultuous manner in carrying out a common purpose," the report added.

After the reading the CIDG report, Philippine National Police Deputy Director General for Operations Benjamin Magalong said it failed to establish the motive of the attack.

Magalong said he ordered Chief Superintendent Eliseo Rasco, CIDG deputy director for administration, to pursue a deeper probe.

Magalong defended Ebreo from lawmakers who grilled him why no charges were filed against the inmates involved.

The inmate liable for Co's death, Clarence Dongail, should be held liable as well as prisoners Edgar Sinco and Tomas Donina.

Investigators said the attempt on Sebastian's life was to prevent him from testifying at the House of Representatives against Senator Leila de Lima.

The person who asked him to stab Sebastian is a former colleague at the Philippine Navy

"Someone from the Navy asked him to do something to silence Jaybee Sebastian so he could not talk against Ma’m Leila ( de Lima) about the proliferation of drugs at the NBP." Ebreo said during the hearing parts of which were aired over ANC.

Ebreo did not say if they have identified the person who gave the order.

De Lima is a critic of President Rodrigo Duterte's war on drugs which has killed about 5,000 people.

Duterte accused her of complicity in the spread of illegal drugs at the NBP through her former driver and alleged lover, Ronnie Dayan. Emmanuel Tupas/DMS