Two key witnesses to the slaying last month of Edgar Damalerio, a Pagadian City television and radio journalist who commented on corruption and other local issues, also received death threats, the Committee to Protect Journalists said.
Damalerio won an Association of Filipino Broadcasters award last year.
His family and one witness have traveled to Manila from Pagadian to press for the arrest of the suspect, Guillermo Wapile, who was released after being questioned.
The National Bureau of Investigation has said it is pursuing charges against Wapile but does not have the power to order him taken into custody.
The witness claimed he was riding in a jeep with Damalerio when the police officer, riding a motorbike with another man, pulled alongside and shot the journalist.
A total of 38 journalists have been killed in the Philippines since 1986.
No one has been convicted for any of the slayings, the committee said. — AFP