The 22 Filipino fishermen of FB GEM-VER which sank June 9 after a "collision" with a Chinese vessel, June 14, 2019. Jeff Canoy, ABS-CBN News

MANILA - Some details in the testimonies of the Filipino fishermen on the allision of their fishing boat and a Chinese ship don't add up, a Palace official said Tuesday.

Presidential Spokesperson Salvador Panelo said the incident must be investigated thoroughly as recent developments show conflicting details between the narratives of FB GEM-VER boat captain Junel Insigne, and its cook Richard Blaza.

"May mga circumstances that give doubt to the version, kaya kailangan imbestigahan na talaga natin. Formal inquiry na kailangan dito," Panelo said during a Palace press briefing.

(There are circumstances that give doubt to the version so we need to investigate it. A formal inquiry is necessary.)

Insigne claimed that the Chinese ship rammed their boat while Blaza, according to Agriculture Secretary Manny Pinol, was unsure whether the Chinese ship intended to do so.

Pinol added that while he considers Blaza the most reliable witness in the incident since he was the only one awake, his claims still need to be investigated and validated by a proper maritime investigating body.

"Of course, sinasabi ng kapitan sinadya, eh sinasabi naman ng cook, mukhang hindi sila nakita. So, with more reason na kailangan mo talaga imbestigahan," Panelo said.

(The captain is saying that it was intentional but the cook is saying that the Chinese ship may not have seen them. So, with more the reason to investigate the incident.)

Defense Secretary Delfin Lorenzana on Monday meanwhile said the government has begun entertaining doubts that the Chinese ship intended to bump the Filipino boat.

"Kasi nga nagkakaroon tayo ng konting doubt kung ano ba talaga ang nangyari dun. Unang natanggap ko nun kaya ako nagpalabas is binangga. Nabangga nga talaga pero was it intentional or not, meron nang doubt ngayon eh kung intentional o hindi," Lorenzana said.

(That's because we are starting to have doubts about what really happened there. What I got first and what I announced was that it was intentional. There was a collision but whether it was intentional or not, there is doubt now if it was intentional or not.)

The Chinese ship reportedly abandoned the 22 Filipino fishermen at sea after sinking their boat. The fishermen were rescued by a Vietnamese fishing vessel.

Beijing's embassy in Manila meanwhile denied this, saying the captain of the ship tried to save them but was "afraid of being besieged by other Filipino fishing boats."