Georgian-born Mikhail Khachidze is accused of gathering intelligence on the Russian army during his service in the North Caucasus Military District, including information on the combat readiness of military units and colleagues.
"During the investigation, conclusive evidence of his spying activity was gathered," the Russian Security Service (FSB) said in a statement. Khachidze, who was allegedly recruited by Georgia in late 2007, faces charges of treason and up to 20 years in jail.
Last week, Russian security forces arrested a top Georgian intelligence officer named only as Kherksladze on charges of collecting data on Russian troops in the North Caucasus and breakaway South Ossetia.
The FSB has detained 10 Georgian intelligence service officers on charges of plotting terrorist attacks, including in Russia. The FSB also said the Georgian secret services had tried to organize underground militant groups in the North Caucasus.
Security was tightened on the Russian border following a major ground and air offensive by Georgia against its breakaway republic of South Ossetia on August 8. The attack prompted Russia to send in tanks and hundreds of troops and eventually expel Georgian troops from the province.
South Ossetia said on Wednesday around 1,500 local residents were killed by Georgian forces during the attack. A total of 37,000 people are reported to have fled across the Russian border.