Illegal trade in Myanmar's jade stones is costing the country billions of dollars anually. Official revenue from jade exports from 2011 to 2014 was $1.3bn, but analysts say trade in 2011 alone was $8bn, suggesting most of the revenue is siphoned off by corrupt officials to fuel Chinese demand. In an exclusive report, a senior government official admits his involvement in the lucrative smuggling trade. Al Jazeera's Chan Tau Chao reports from Northern Myanmar.