A spokesman for the National Security Council (NSC) of the Philippines on Thursday said some information on the country's resupply missions in the South China Sea was compromised and passed on to Chinese intelligence agents.
His statement came a day after the Philippine Government said it apprehended some of its citizens on suspicion of spying for China in a "serious national security matter."
NSC spokesman Cornelio Valencia called the breach "alarming" but limited in scope, adding that the channels used to transmit the information had been shut down.
"Rotation and resupply data fall under operational security because disclosing it can endanger personnel, and that has been compromised," Valencia said.
Philippine and Chinese vessels have frequent run-ins during Manila's resupply missions to its occupied features in the South China Sea. And Chinese diplomats, Philippine lawmakers, and a coast guard spokesperson have recently engaged in heated public exchanges over the disputed waterway. Valencia said three Filipinos had been apprehended and, "there could be more." He declined to say whether charges would be filed.
Reuters spoke with the three accused people last month under an agreement with security sources on the condition that their identities not be revealed. One of the accused, who obtained information on deployments, resupply runs and personnel rotations through a connection with a Philippine Coast Guard staffer, said he passed the details to his contact using a phone issued to him.
The accused showed Reuters the phone, which contained a Tetris game that, when a code was entered, opened a hidden messaging platform that he said he used to communicate with his handler. "What I can say is that they're cooperating with our security services," Valencia said. "They have confessed and admitted to it. They disclosed the data that they were able to get and share, the assessments they made and how they were recruited."
China's Foreign Ministry rejected the Philippines' accusations, saying on Thursday: "We object to it, the case is not clear and there is no conclusive evidence."
Another accused person told Reuters that he was initially approached by a Filipina acquaintance when he was a junior staffer at the Department of National Defence with an offer to write opinion articles in return for money. That later expanded to providing information related to the South China Sea and the defence ministry's bilateral engagement with Philippine allies, including the US, he said.
He did not immediately realise he was working for Chinese agents and only became suspicious later, but it was hard to stop as he needed the money, he said, adding that he did this work between 2023 and 2025.
The recruitment pattern mirrors methods seen in other foreign intelligence operations, where seemingly innocuous offers of consultancy or writing work are used as entry points before escalating into requests for sensitive material.
Last year, Reuters reported that networks linked to Chinese actors have used consulting firms and covert job offers to lure targets, often exploiting financial vulnerabilities and gradually seeking more sensitive information, a pattern analysts say follows techniques used by previous Chinese intelligence operations.
Philippine lawmakers from both the ruling party and the opposition are seeking to overhaul decades-old espionage laws that would expand their traditionally wartime focus to cover peacetime and cyber-enabled threats.
(Reporting by Karen Lema; Editing by Thomas Derpinghaus)