West PH Sea: Cyanide found in bottles from Chinese boats near Ayungin

MANILA, Philippines — Laboratory tests found cyanide in several bottles recovered by the Philippine Navy from Chinese boats operating near BRP Sierra Madre at Ayungin Shoal last year, the National Security Council (NSC) said Monday.

Cyanide is a “highly toxic chemical known to cause severe and irreversible damage to humans and marine ecosystems,” the NSC said.

“Laboratory analysis conducted by the National Bureau of Investigation’s Forensic and Scientific Research Service has conclusively established that the yellow bottles seized from the sampans contain cyanide,” the agency explained.

READ: Bottles of ‘cyanide’ seized from Chinese fishers

The bottles were seized from Chinese boats in February and October 2025.

Citing the potential damage to the West Philippine Sea’s environment and its impact on Filipino military personnel on the BRP Sierra Madre as well as local fisherfolk, the NSC maintained that, if proven to be intentional, the use of cyanide could constitute a violation of international law.

“The use of cyanide in Ayungin Shoal is a form of sabotage that seeks to kill local fish populations, depriving Navy personnel of a vital food source. Moreover, cyanide can damage the reef which can ultimately compromise [the BRP Sierra Madre’s] structural foundations,” the NSC stressed.

“If the reef is severely damaged, it not only threatens [the BRP Sierra Madre’s] stability, it also allows Beijing to fabricate an environmental crisis which it can then blame on the Philippines. It has in the past accused [the BRP Sierra Madre] of polluting the shoal in an effort to distract from its own illegal activities,” it added.

READ: PH to build case on Chinese fishers’ alleged cyanide use in WPS

Given this development, the NSC ordered the Armed Forces of the Philippines and the Philippine Coast Guard to intensify its monitoring of the area.

The BRP Sierra Madre is a landing ship tank intentionally grounded by the Philippine Navy in 1999 to serve as a military outpost near the Ayungin Shoal, an area inside the Philippines’ exclusive economic zone and a flash point of tension between Manila and Beijing. /dl