The 12th person detained for allegedly spying for Russia worked as an entry-level software tester at Microsoft for nine months, the company has confirmed.
Alexey Karetnikov was deported to Russia on Tuesday after he admitted to an immigration judge to being in the US illegally, according to a report in the Washington Post, citing anonymous federal law enforcement officials.
Microsoft then issued a short statement confirming the status of Karetnikov's employment.
One law enforcement official told the Post there was insufficient evidence to charge Karetnikov with a crime. The Russian had "just set up shop" and was in the early stages of his mission.
A Facebook profile for a person named Alexey V Karetnikov says he graduated last year from St Petersburg State Polytechnic University and is married. His current employer is listed as Microsoft, with a previous job as a senior developer at a company called Neobit.
Karetnikov was apparently not connected with 10 other Russians accused of acting as unregistered agents for the Russian government. The 10 suspects pleaded guilty last week in a New York court to various actions, including secretly communicating with Russia and facilitating money transfers.
A judge then expelled them from the country. The U.S. and Russia agreed to a spy swap in Vienna, and a day later the 10 agents were handed over to Russia in exchange for four people accused of spying for the U.S., bringing an apparent end to a highly publicised case.