MANILA - (UPDATE) Former Philippine National Police Chief Ronald "Bato" dela Rosa, who was once at the forefront of President Rodrigo Duterte's war on drugs, filed his certificate of candidacy (COC) for senator on Friday.

Dela Rosa said he would push for reforms in the police force and the restoration of the death penalty if he is elected senator in May 2019.

"Restoration of death penalty agad [for] drug trafficking and other heinous crimes like rape, murder, talagang karumaldumal," Dela Rosa told reporters after he filed his COC.

He formally filed his Senate bid at the Comelec office shortly before 11 a.m. due to the advice of a "Feng Shui expert."

"Sabi sa Feng Shui, mag-file at 11 a.m. kasi ganung oras daw, the sun is directly above you," he said.

"So lahat ng energy ng sun mapupunta sa ulo ni Bato," he said in jest.

The former police general from Davao City earlier said he might run for Davao del Sur governor but eventually changed plans after receiving Duterte's endorsement.

"Before kasi sabi niya (Duterte), 'Takbo kang gobernador,' pero nagbago isip niya, sabi takbo na senador," Dela Rosa said.

"Baka nakikita rin niya na pumapasok [ako] sa mga survey, sabi niya, 'Grab the opportunity,'" he said.

It will be the 56-year-old Dela Rosa's first foray into politics. He was appointed director general of the Bureau of Corrections after he retired from the PNP in April with the four-star rank of director general.

• Dela Rosa is next Bureau of Corrections chief

"Gustong-gusto kong magserbisyo. I am too young to retire. Malakas pa ako, marami pa akong mabigay na serbisyo sa taongbayan," he said when asked why he decided to bid for an elected post.

Dela Rosa is part of the President's national party, Partido Demokratiko Pilipino-Lakas ng Bayan, and Hugpong Ng Pagbabago, the regional party of Davao City Mayor Sara Duterte.

If successful, he will be the second former PNP chief to be elected to the Senate after incumbent Panfilo Lacson, who rose to fame fighting kidnap for ransom rings.

Dela Rosa rose up the ranks in the police force. He was once assigned as provincial director of Compostela Valley and Davao del Sur before he served as Davao City police chief from 2012 to 2013 when Duterte was mayor.

As PNP Chief, Dela Rosa implemented on a national scale, Oplan Tokhang, Duterte's anti-drug campaign in Davao, but said that he is willing to look into alleged extrajudicial killings (EJK) should he win a Senate seat.

"Palagi kong sinasabi na imbestigahan yan, managot ang dapat managot kung may EJK talaga ha," Dela Rosa said.

"I do not condone. Ako mismo galit na galit ako sa EJK. Gawain yan ng mga walang b*yag," he said.