Russian security service says Col. Vadim Leiderman approached a number of Russian state workers for secret military information.  
Col. Vadim Leiderman, Israelís military attachÈ who was expelled from Moscow, was trying to obtain details about Russia’s arms trade with the Arab world, Russia’s Federal Security Service (FSB) said Friday, AFP reported.

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, as cited by AFP. It added that Russia had decided to keep the expulsion secret as a "gesture of goodwill."

Leiderman was arrested last Thursday by Russian security services and questioned about allegations that he had been spying on Israelís behalf. He was told he had 48 hours to leave the country, and he returned to Israel last weekend, two months before the end of his term.

While Israel denied that Leiderman had been involved in espionage, the Russian news agency Novosti reported on Thursday that the Israel Air Force officer had been helping Israeli defense industries illegally obtain sensitive technology.

ìThis deals entirely with industrial espionage ñ or rather, his overly active work on behalf of certain Israeli companies on the Russian market,î a Russian security source was quoted in the media as saying.

Russiaís Foreign Ministry issued a statement on Thursday saying Leiderman was caught ìred-handed... receiving secret information from a Russian citizen.î

Israeli-Russian defense ties have improved in recent years, as Moscow canceled the delivery of the S300 Air Defense System to Iran, and in return Israel agreed to sell Russia the rights to manufacture unmanned aerial vehicles developed by Israel Aerospace Industries.

Israel is reviewing several Russian requests to buy Israeli military hardware, and it is possible that Leidermanís deportation will have affect the deliberations.

Israeli drones sold so far to Russia ñ which issued a requirement document for unmanned aerial vehicles after its war with Georgia in 2008 ñ have been older models due to concerns the technology would be transferred to Arab countries.

Russia has expressed interest in Israel Aerospace Industriesís more advanced drones, such as the Heron, which can stay airborne for more than 24 hours and has a range of thousands of kilometers, as well as the ability to carry many types of payloads.

It is also interested in additional Israeli-made intelligence platforms, as well as command- and-control systems to upgrade communications within its military.

The IDF and the Defense Ministry are discussing whether they should send a new attachÈ to Moscow or keep the position empty to protest Leidermanís expulsion.

ìEverything is under consideration,î a senior defense official said on Thursday. ìWe will hold discussions over the coming days and hope to be able to put this behind us as soon as possible.î

The Foreign Ministry declined all comment