A federal judge has sentenced a man to serve 6.5 years in prison – the maximum permitted sentence – and pay restitution of $100m to Cisco for his role in leading a massive scheme involving the sale of counterfeit Cisco equipment across the globe.

Onur Aksoy (40), a Miami, Florida resident with dual US and Turkish citizenship, pleaded guilty last year to charges related to the importation of hundreds of millions of dollars in counterfeit Cisco networking equipment from China and Hong Kong and then selling it on via a network of at least 19 companies, 15 Amazon storefronts and 10 eBay accounts.

Other victims of the counterfeiting are also due restitution amounts that will be determined at a later date, according to a Department of Justice statement.

The devices the network imported were typically older, lower-model products – some of which had been sold or discarded – which Chinese counterfeiters then modified to appear to be genuine versions of newer and more expensive Cisco devices, often with pirated Cisco software and unauthorised, low-quality, or unreliable components.

The knock-off computer networking equipment ended up in US hospitals, and schools, as well as military and other governmental systems including platforms supporting US fighter jets and military aircraft.

“Criminals who flood the supply chain with low-quality networking equipment from China and Hong Kong harm US businesses, pose serious health and safety risks, and compromise national security,” said principal deputy assistant attorney General Nicole Argentieri, who heads the DoJ’s criminal division.

Aksoy pleaded guilty to conspiring with others to traffic in counterfeit goods, to commit mail fraud, and to commit wire fraud, as well as mail fraud.

Amazon’s Counterfeit Crimes Unit, which referred the case to law enforcement with Cisco, said the sentencing “sends a strong message to others that attempting to sell counterfeits in the Amazon store, or elsewhere, comes with severe consequences, and that we will continue to partner with others to hold bad actors accountable.”