MOSCOW - An Israeli military attache to Moscow who was expelled from Russia last week was carrying secret information when he was detained, Russia's Foreign Ministry said on Thursday.

Vadim Leiderman was apprehended in Moscow on May 12, caught red-handed receiving classified information from a Russian citizen, the statement said. Leiderman was declared persona non grata and given 48 hours to leave the country, which he did, the statement said.

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Israel's military, however, has rejected allegations that Leiderman was a spy, saying in a statement Wednesday that the officer underwent a "thorough investigation" after he returned.

Gad Shimron, an intelligence expert and former field operative for the Mossad, told Israel's Channel 10 TV that based on the information he knows the odds of Leiderman being a spy are "extremely small."

"A military attache by definition openly gathers and relays information so its pretty stupid to get a military attache involved in spying, its a waste of time," Shimron said.

"According to the little information I am getting, it appears there might be some kind of squabble between the Russian military intelligence and the FSB and somebody decided to flex their muscles to the other. I think the military attache fell victim to an internal Russian spat and had nothing to do with anything."

Some Israeli media reported Leiderman was taken away by Russian agents during dinner, while others said he was having coffee with a friend before being pulled away by security agents.