With the iPhone 6 and 6 Plus continuing to be hot items in China, there is no shortage of people churning out counterfeit products to cash in on Apple’s cachet.

Beijing police say they have busted the city’s biggest-ever international counterfeiting ring that sold over 41,000 fake iPhone 6 units to the USA worth RMB 120 million ($19.6 million).

Nine suspects are in custody after police uncovered a sophisticated operation that employeed hundreds of employees to staff the factory’s six assembly lines. More than a million spare parts were found.

Police say a man named Yu and his wife began the operation in 2011 by opening a factory in Beijing’s Shunyi District. Used motherboards were purchased abroad and then assembled with fake parts stamped with authentic-looking logos from Shenzhen.

Police began a investigation after fake iPhones were discovered on sale in the USA.

The name of the company producing the counterfeit iPhones has not been revealed by police, who call the case “the first of its kind” in the city.