Russia threatens to retaliate after authorities arrested Artyom Uss, the son of a top Russian official, at the United States’ request, for allegedly participating in a sanctions evasion and money laundering scheme.

Uss, who was detained in Milan, was charged in relation to a scheme to unlawfully obtain U.S. military technology and sanctioned Venezuelan oil in order to support Russia’s war effort in Ukraine, according to charges unsealed by the U.S. Department of Justice this week.

Kremlin spokesman Dmitry Peskov said “We are categorically against this and we condemn the practice of these kinds of arrests of Russian citizens”.

Uss’ father, the governor of Russia’s Krasnoyarsk Krai region, Alexander Uss, has suggested the arrest is politically motivated.

Another Russian government spokesperson, Maria Zakharova, said Moscow would not leave the United States’ search for Russians “unanswered” and accused the U.S. of “taking hostages for political purposes”.

Uss wasn’t the only one charged in the money laundering and smuggling scheme. Uss co-owned a trading company called Nord-Deutsche Industrieanlagenbau GmbH (NDA GmbH) which he and co-conspirators allegedly used as a front to ship U.S. defense technology to Russia.

Uss Accused of using NDA GmbH to Ship Advanced Semiconductors

Uss and co-conspirators are accused of using NDA GmbH to ship advanced semiconductors and microprocessors for fighter aircraft, missile systems, smart munitions, radar, and satellites to Russia— some have been found in weapons used in the war in Ukraine.

“Some of the same electronic components obtained through the criminal scheme have been found in Russian weapons platforms seized on the battlefield in Ukraine,” the Department of Justice said in an announcement, adding that the accused developed a “sophisticated network” of schemes that “undermined security, economic stability and rule of law around the world.”

The group of co-conspirators also allegedly shipped hundreds of millions of barrels of oil from Venezuela to Russian and Chinese entities, including at least one sanctioned oligarch.

The 12-count indictment charged five Russian nationals in total, including Yury Orekhov, Svetlana Kuzurgasheva, Timofey Telegin, and Sergey Tulyakov. Juan Fernando Serrano Ponce and Juan Carlos Soto were also charged with setting up illegal oil deals for Venezuelan state oil company Petroleos de Venezuela S.A.

One of the co-conspirators openly acknowledged that NDA GmbH was working for a sanctioned oligarch, according to court documents. “He [the oligarch] is under sanctions as well, that’s why we [are] acting from this company [NDA GmbH],” Orekhov said.

Russia has long helped Venezuela evade sanctions around the globe. But the latest charges expose the multiple layers of sanctions the United States has imposed on both Russia and Venezuela.

The United States has been sanctioning Venezuela for more than 15 years, and in recent years has imposed restrictions on Venezuela’s state oil company and other entities in order to try to pressure Venezuelan dictator Nicolás Maduro to leave power.

Sanctions on Russian banks in recent months, which the United States and other nations have levied in an attempt to try to isolate Moscow on the world stage while it assaults Ukraine, have likely hurt Venezuela’s ability to access its assets, according to the Congressional Research Service. But higher oil prices from Russia’s invasion of Ukraine appear to be driving a semblance of economic recovery for Venezuela, according to the CRS.