Investigators have identified a person of interest in the fatal shooting of a radio broadcaster in Oriental Mindoro province this week, police said on Thursday.

Cresenciano Bunduquin, 50, was killed by motorcycle-riding gunmen in Calapan City on Wednesday.

One of the assailants died after Bunduquin's son hit the gunmen with his vehicle as they fled the scene of the pre-dawn attack. The remaining suspect was able to run off.

"Sa ating mga nakuhang ebidensya, mayroon po tayong positive na person of interest na na-indentify. Mamaya po, kukuhanan namin ng salaysay iyong dalawang witness," Oriental Mindoro Provincial police chief Col. Samuel Delorino said.

"Kung ito ay maikukumpirma niya na iyon talaga, positive na masasabi natin na maso-solve natin iyong kaso natin at maifa-file natin sa madaling panahon," he told ABS-CBN's TeleRadyo.

(Based on the evidence we recovered, we have identified a person of interest. We will get the statement of the 2 witnesses. If they can confirm that this is the person of interest, we can solve the case and file charges immediately.)

Bunduquin hosted a program on radio station 101.7 DWXR as well as on Facebook, said station manager Jester Joaquin, who described the broadcaster as "hard-hitting" on local issues.

He had been outspoken about a recent oil spill affecting the province, illegal gambling and politics.

"He told me before that he's receiving threats but he didn't elaborate," Joaquin told AFP.

"He mentioned to me that he wanted a change in his line of work, that's why he put up a chicken farm, because he wants to go quiet."

Investigators are looking into Bunduquin's work or a personal quarrel as possible motives for the killing, Delorino said.

"Lahat po ay iniimbestigahan natin at kapag nasuri po iyong mga cellphone ng biktima at suspek, magkakaroon tayo ng isang magandang analysis kung ano talaga ang motibo ng pagkakapaslang sa kanya," he added.

(We are investigating everything, and once we comb through the cellphone of the victim and the suspect, we will have a good analysis of the motive.)

Bunduquin is the third journalist to be killed since President Ferdinand Marcos took office last June.

The latest killing comes less than a year after radio personality Percival Mabasa was shot dead in Manila as he drove to his studio.

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"Bunduquin's killing further shows that journalists in the Philippines still operate under threat despite our improvement in the press freedom index and the relatively friendlier relations that media has with the current administration," said Jonathan de Santos, chairman of the National Union of Journalists of the Philippines.

"When perpetrators of attacks on media are not held to account and victims of these attacks do not get justice, future attacks become more likely."

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— With a report from Agence France-Presse