Three supervisors of the US government’s controversial anti-gun-running program “Fast and Furious” were promoted by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) despite continued criticism of their actions, the Los Angeles Times reported Tuesday.

The men helped coordinate the large-scale sting operation, which saw thousands of firearms illegally trafficked between the US and Mexico in a bid to ensnare gangs and drug cartels.

No senior crime figures were arrested during the 15-month program, which also was linked to the shooting deaths of two US Border Patrol agents. The program reportedly became so unwieldy that the ATF lost track of more than a thousand firearms and played an active role in arming the Sinaloa cartel, one of Mexico’s most vicious crime units.