Four paramilitary CIA officers drowned during a clandestine mission to place an underwater device designed to monitor Chinese military activity in the South China Sea, it has emerged.
The 2008 operation ended in failure when the men were swept away by a tropical storm while they were trying to place a surveillance pod disguised as a rock off the Philippine island of Luzon.
This was five years before China began to build artificial islands on coral reefs and atolls in the South China Sea for military purposes, leading to heightened tension with the US and regional neighbours who remain in dispute with Beijing over ownership of territory.
Two of the CIA operatives, Stephen Stanek and Michael Perich, both trained scuba divers, were tasked with placing