MANILA, Philippines - A team of policemen from Metro Manila went to Bicol region on Tuesday to dig deeper into the murder of jueteng whistleblower Wilfredo "Boy" Mayor in Pasay City over the weekend.

Senior Superintendent Raul Petrasanta, Pasay City police chief and commander of Special Investigation Task Group Mayor, said the team of investigators will interview people who worked and transacted with Mayor in the region.

Petrasansa added that that they are looking into 3 possible angles in the murder of the whistleblower. He said that aside from jueteng, Mayor could have also been killed because of his job as a contractor and his frequent visits in casinos.

He said the investigating team will also look for Mayor's relatives and convince them to talk and possible lead them to the murder's mastermind.

Former Lingayen-Dagupan Archbishop Oscar Cruz, who gave protection to Mayor when he came out to reveal the alleged link of First Gentleman Mike Arroyo to the illegal numbers racket, said the killing could have been connected to an alleged anomaly regarding construction projects in Albay that were funded using the Countrywide Development Fund (CDF) pork barrel.

He said Mayor was about to expose the people behind a big corporation that has been bagging all construction projects in Albay.

Sandra Cam, another jueteng whistleblower, said Mayor had also told her about a certain Zaldy Co, the supposed big-time contractor, who has allegedly cornered all government contracts in the Bicol region.

She said Mayor called her up last week and explained that he was fearful for his life because he had an argument with Co's brother over a construction contract.

He said Mayor was gathering hard evidence against the big-time contractor when killed on Sunday.

Mayor had just left the City State Hotel and Casino in Malate, Manila around 4 a.m. with his nephew, Rommel Paje, and son-in-law, Allan Benedict Castro, when two motorcycle-riding men opened fire at their Volvo vehicle.

The whistleblower was declared dead on arrival after being brought to the San Juan de Dios Hospital in Pasay City. With a report from Jon Ibañez, radio dzMM