It was around 10 a.m. on Sept. 22 when the raid on the pig farm began. Accompanied by fire and sanitation officials, a police team entered the compound at the foot of the extinct volcano Mount Arayat, north of Manila, on the pretext they were conducting a safety inspection.

They didn't find any pigs. What they did uncover, in a hangar larger than a football field, was a raised platform supporting a diesel generator, an industrial chiller and distillation equipment — all for the production of the highly addictive drug methamphetamine. The industrial-sized laboratory, the police report said, was capable of producing at least 200 kg a day of meth. Around that time, a kilogram of meth had a street value of $120,000, the police said.

Philippine law enforcement authorities had been alerted to the farm by locals who reported spotting vehicles with "Chinese-looking men" entering at night and leaving before dawn. During the raid, police arrested Hong Wenzheng, a 39-year-old Chinese national from Fujian province who is now in prison awaiting trial. Four other men believed to be Chinese nationals escaped and are the target of a manhunt.