Moscow is planning to release a Russian arms expert convicted of espionage in exchange for members of the alleged spy ring arrested in the United States, a lawyer said on Wednesday.
Anna Stavitskaya, lawyer for Igor Sutyagin, said he had informed his relatives that he was to be released as part of such an exchange between Moscow and Washington.
"He is going to be exchanged for the people who are being accused of espionage in the United States," Stavitskaya told a news conference.
Russian arms expert Sutyagin was convicted in 2004 of handing over classified information to the United States, via a British security company that Russia claimed was a CIA cover, and sentenced to 15 years in jail.
Sutyagin's brother Dmitry told the same news conference that Sutyagin would be transferred to Vienna, from where he would fly on to London. There was no comment on the claims from Russian authorities.
The comments came as three alleged members of a Russian spy ring were to appear in court on Wednesday in Alexandria, Virginia accused of operating deep under cover for the Kremlin in the United States since the 1990s.
The defendants are among 10 alleged Russian "deep cover" sleeper agents arrested on June 27 in an FBI swoop.
An 11th suspect, accused Kremlin paymaster Christopher Metsos, was arrested in Cyprus the following day but freed on bail and subsequently vanished.
Dmitry Sutyagin said that his brother had told the family that the suggestion from the exchange had come from the American side.
"The Americans presented a list of people for whom they were ready to exchange the people detained in America accused of espionage. Igor was among them."
Sutyagin "was told three or four surnames literally, not 11, but apparently they must exchange 11 (people) for 11," his brother Dmitry said.
"They explained quite clearly that if even one person from this list refused, then the agreement would fall apart."
Sutyagin met his mother and brother earlier Wednesday after officials at Moscow's Lefortovo prison called to arrange a visit, they said.
He had been transferred to Moscow from his prison in the Russian Far North earlier this week, they added.