Moscow: The Israeli military attaché expelled from Moscow was trying to obtain details about Russia`s arms trade with the Arab world, the country`s powerful Federal Security Service (FSB) said on Friday.
Russia`s Foreign Ministry said that Soviet-born Colonel Vadim Leiderman was "caught red-handed" while trying to receive secret information on May 12.
RBC television channel later aired footage of a man identified as Leiderman being approached by several men while he was dining with another man in a Moscow restaurant.
The Israeli official was then shown being interrogated in a Russian office, with his various accreditation and bank cards being laid out on a table for the camera.
His expulsion sparked protests in Israel and was the first such incident to occur between the two countries in nearly 20 years.
An unnamed Russian security official told news agencies on Thursday that Leiderman had engaged in industrial espionage.
But the FSB issued an official statement on Friday saying the attaché was trying to collect details about Russia`s arms trade with its Soviet-era partners in the Arab world.
Leiderman had approached "a number of Russian state workers for secret information about ... Russia`s military and technological cooperation with -- and assistance for -- a number of Arab nations," the FSB statement said.
It added that Russia had decided to keep the expulsion secret as a "gesture of goodwill”.
The information about Leiderman`s expulsion initially appeared in Israel and was sourced to local defence officials.
The FSB said the Israeli media leak left it "seriously perplexed".
Israeli media reports said the brief detention and search prior to Leiderman`s expulsion appeared to breach his diplomatic immunity. Channel One television said he was the first Israeli military official to be expelled from Russia since the early 1990s.
Russia and Israel now enjoy close economic ties based on the Jewish state`s vast ex-Soviet Diaspora.
But Russia is also a key arms supplier to the Arab world and continues to sell advanced missile systems to Syria that Israel fears make their way to the Shi’ite Hezbollah movement in neighbouring Lebanon.