He's hiding out in the mountains of the Golden Triangle Special Region. It sits at the intersecting point of Thailand, Laos and Myanmar. It's under the three countries' jurisdiction, but its location makes law enforcement almost impossible. Adding corruption into the equation, the region is a "No Man's Land", a paradise for criminals.
We found out that he has been producing meth with raw ingredients bought via a middleman.
It's medicinal ephedra.
We got that thing... Too bad we didn't meet earlier. It's "Xiang Feng Hen Wan." (相逢很晚)