Alexandr Zhitnyuk is accused of treason for passing state secrets to the CIA, reported the Rosbalt news agency.
He was detained after a “special operation” which allegedly found he had handed over naval secrets to US intelligence.
‘As a result of observation it was established that Zhitnyuk passed information containing state secrets to representatives of Western intelligence,” a source was quoted as saying.
“The final beneficiary of this information was the Central Intelligence Agency of the USA.
The secrets related to Russia‘s naval fleet.
No more details were given.
The FSB claims there has been a rise in US intelligence operations in recent months in former Soviet countries.