Gold bars fraudulently stamped with the logos of major refineries are being inserted into the global market to launder smuggled or illegal gold, refining and banking executives tell Reuters. The fakes are hard to detect, making them an ideal fund-runner for narcotics dealers or warlords.

In the last three years, bars worth at least $50 million stamped with Swiss refinery logos, but not actually produced by those facilities, have been identified by all four of Switzerland’s leading gold refiners and found in the vaults of JPMorgan Chase & Co., one of the major banks at the heart of the market in bullion, said senior executives at gold refineries, banks and other industry sources.