Legal sources tell NBC News that the former second ranking officer in the U.S. military is now the target of a Justice Department investigation into a politically sensitive leak of classified information about a covert U.S. cyber attack on Iran’s nuclear program.

According to legal sources, Retired Marine Gen. James “Hoss” Cartwright, the former vice chairman of the Joint Chiefs of Staff, has received a target letter informing him that he’s under investigation for allegedly leaking information about a massive attack using a computer virus named Stuxnet on Iran’s nuclear facilities. Gen. Cartwright, 63, becomes the latest individual targeted over alleged leaks by the Obama administration, which has already prosecuted or charged eight individuals under the Espionage Act.

Last year, the New York Times reported that Cartwright, a four-star general who was vice chairman of the Joint Chiefs from 2007 to 2011, conceived and ran the cyber operation, called Olympic Games, under Presidents Bush and Obama. According to the front-page story by chief Washington correspondent David Sanger, President Obama ordered the cyber attacks sped up, and in 2010 an attack using the Stuxnet worm temporarily disabled 1,000 centrifuges that the Iranians were using to enrich uranium.