Lagos – Nigerian drug agents arrested four Mexicans who were allegedly helping build a “super-lab” capable of producing billions of dollars’ worth of methamphetamine, the National Drug Law Enforcement Agency said Monday. Spokesman Mitchell Ofoyeju said it was the first industrial-scale production of crystal meth found in West Africa, and possibly on the continent. “The Nigerians invited the Mexicans in to leverage their expertise in these industrial-scale, high-yield productions,” said Ofoyeju. The warehouse in southern Delta state could produce 4,000 kilograms (8,800 pounds) a week of the synthetic drug, which sells for $6,000 a kilogram in Nigeria but as much as $300,000 a kilogram in the Asian markets favored by Nigerian drug dealers, Ofoyeju told The Associated Press. Most goes to Singapore and Malaysia.