Manila: An ex-governor of Palawan in southwestern Philippines was finally charged for the killing of a hard hitting journalist and environmentalist in January 2011, reversing an old ruling following the emergence of new evidences and the intensification of campaign on social media by those who were outraged by the government official's earlier exoneration, prosecutors said.

Joel Reyes, former governor of Palawan, his brothers and three others were finally charged for the murder of Gerry Ortega who was shot dead while he was in a second hand clothes shop in Puerto Princesa, after his radio talk show, last January 2011, the prosecutors of the department of justice said in a written resolution.

"It is believed that the radio commentaries of Dr. Ortega (in his talk show), who is also a keen environmental activist, against Reyes... served as motive for the conspiracy to murder him," the prosecution panel said.

When he was alive, Ortega, also known as Doc Gerry, accused Reyes of massive corruption and alleged misuse of revenues in hundreds of millions of dollars from a major offshore gas field in Palawan.

At the time, Ortega also called for intensified protest against the mining activities approved by Reyes, adding it destroyed the environment of Palawan, an eco-tourism destination.

After Ortega's murder, a hitman was caught immediately. His gun was traced as owned by a close aide of ex-governor Reyes.

A member of the murder team decided to become a state witness and implicated Reyes for the murder. But at the time, the prosecutors junked this testimony, saying it was a hearsay.

After the Ortega family campaigned for a year for reinvestigation, it resulted in the replacement of the prosecution panel that exonerated Reyes, his brother, and several others.

In the online campaign, the complaining family members of Ortega said that the erroneous exoneration of Reyes further strengthened abuse of powerful people, adding that erring powerful people should no longer remain unpunished.

Influential church members and rights groups were also part of the campaign that went viral online.

Reyes continued denying his participation in Ortega's murder.