Philippine police have charged a Japanese national, his Filipino wife and four Filipino men for the murder of a Japanese travel executive in Manila in early May, a police official said Tuesday. The suspects remain at large.

Hiroshi Iwasaki, 59, was shot dead at close range by gunmen riding a motorcycle on May 6 in Paranaque City on the outskirts of Manila while he was driving home.

Police investigator Christopher Bilangel said that Yoshikazu Ogura, his Filipino wife, Edna, and the four other suspects were charged two weeks ago at the prosecutor's office.

Bilangel said the killing was related to a dispute over a loan Iwasaki made to Ogura.

Iwasaki had lived in the Philippines for at least 19 years, police records show.