TAIPEI -- A Taiwan investigation team sent to Manila to probe a fatal shooting of a Taiwanese fisherman by Philippine coast guard returned to Taipei on Saturday, calling Philippines' attitude on a joint investigation "capricious."

Chen Wen-chi, head of the Taiwanese investigation team, said the team has been negotiating with the Philippine government on a joint investigation, but the Philippines' attitude was capricious and its response was unacceptable.

The Taiwanese team arrived in Manila on Thursday to investigate the shooting of a Taiwanese fishing boat by Philippine coast guard on May 9, which caused the death of 65-year-old fisherman Hung Shih-cheng.

Chen slammed Philippines' allegation that the shooting was in self-defense, saying shooting was beyond normal law enforcement activities. She also urged the Philippine government to provide evidence for its allegation that the victim was the "villain."

The island's justice authority, in a statement issued Saturday, also criticized the Philippine government's "lack of sincerity and credibility" in cooperating with the island's investigation team, saying the Philippines had previously approved the joint investigation but then "prolonged and delayed" the investigation team's requests.

Chen said Taiwan will continue to negotiate with the Philippines but she did not respond to reporter questions whether the island will send an investigation team to Manila again.