Philippine police are investigating whether two Japanese men may have been involved in the motorcycle slaying of a 32-year-old Japanese businessman over the weekend, a police official said Monday.

Police officer Rey Viloria said one of the two unnamed individuals was in a taxi with Shinsuke Toba, of Yamanashi Prefecture, when a gunman on a motorbike rode up and shot Toba dead at point-blank range.

The attack happened at around 11:30 p.m. Saturday in a dimly lit street in the Las Pinas neighborhood of Metro Manila.

Toba had arrived in Manila the previous day.

The cab driver told police that the victim's companion, who was in the front passenger seat, instructed him to pull over at the roadside to urinate. The shooting then took place and the man disappeared.

"So, this Japanese man is a person of interest for now," said Viloria.

He said the other "person of interest" is a Japanese man who had dinner with the victim at around 10 p.m. Saturday at a steak house in the Malate suburb.

"We are tracing the whereabouts of these two men," Viloria said, adding the police are looking for a motive for the killing.

Police found a bullet casing inside the taxi, as well as the victim's mobile phone and a shoulder bag containing cash and other personal effects.

Toba died at a hospital from gunshot wounds to the face and body.