Singaporean Stanley Jang, 36, was killed in Parañaque City on Wednesday (Aug 5) after two gunmen wearing caps entered his office and shot him.
He was shot once in the left side of the face by a shot gun round and died on the way to hospital.
The incident happened around noon in the commercial area of Don Bosco in the city, which is about 20km south of Manila.
Speaking to The New Paper, Chief Inspector Arnold Dugas from the city police said that the gunman, who were carrying shotguns, had not been identified and no items were taken from the office.
He added that the office is located in the commercial area of the city that is "not that dangerous and is a peaceful area".
Mr Jang, who owns an electronics company, has been living in the Philippines for over 10 years with his Filipino wife and two-year-old child.
His cousin told TNP that Mr Jang had been planning to surprise his parents by coming home to Singapore for the Jubilee weekend.
"The fact that he was planning to give them a surprise and spend the long weekend with them shows how much he cared for them," said the cousin, who gave his name as Mr Han.
The police have not determined a motive for the killing and are putting together a special team to investigate the shooting.