Russia is reportedly working out a deal with U.S. authorities to reclaim its suspected spies recently arrested in the United States.
The swap involves jailed nuclear researcher Igor Sutyagin, his brother and lawyer have said.
Igor Sutyagin, a Russian national, was sentenced to 15 years in jail in 2004 for allegedly passing classified Russian military information to a British firm that prosecutors claimed was a CIA cover.
He has always maintained his innocence, saying the information he provided was available from open sources.
His brother, Dmitry, told a news press conference in Moscow that Igor Sutyagin will be released from jail on July 8.
"Tomorrow, Igor will be sent to Vienna and then from Vienna to London," Dmitry Sutyagin said. "So we are not going to be able see him any time soon."
Dmitry Sutyagin said officials met his brother on July 5 at a prison in the northern Russian city of Arkhangelsk. He said U.S. officials were also at the meeting.
News of the possible swap emerged after Sutyagin was moved this week from prison in Arkhangelsk to Moscow's Lefortovo prison and allowed to see his family.
Anna Stavitskaya, a lawyer acting for Igor Sutyagin, said he was made to sign a declaration of guilt.
"Although he agreed to sign the documents that were given to him and that he didn't really read through, he wants to say that, regardless of all that, he wants everybody to know that he never committed this crime and he considers himself innocent," Stavitskaya said.
Stavitskaya said her client would be exchanged for just one of the 10 members in the alleged spy ring arrested last month on suspicion of seeking to infiltrate U.S. policymaking circles on behalf of Russia.
Another suspect was detained in Cyprus last week but disappeared after being released on bail.
According to his brother, Sutyagin was shown a list of 11 people to be included in the swap. Sutyagin reportedly recognized only the name of Sergei Skripal, a Russian Army colonel sentenced in 2006 to 13 years in prison on charges of spying for Britain.
Neither Russia's Foreign Ministry nor its Foreign Intelligence Service (SVR) and Federal Penitentiary Service have commented on the reported spy swap.
Moscow and Washington have agreed to such swaps in the past.
One of the most famous instances was the exchange of Russian spy Rudolf Abel for Francis Gary Powers, whose U-2 spy plane was shot down over the Soviet Union in 1960.
Meanwhile, in Washington there were signs that a deal might be afoot.
Undersecretary of State for Political Affairs William Burns, a former U.S. ambassador to Moscow, met with Russian Ambassador Sergei Kislyak.
State Department deputy spokesman Mark Toner said the case of the alleged spies wasn't the primary purpose of the meeting -- he said the focus was on follow-up to Russian President Dmitry Medvedev's June 23 White House visit -- but added, "I believe the case was discussed."
"Did the spy case come up? Likely it did," Toner said. "Am I going to get into the details? No."
He referred reporters to the Justice Department, calling the case an "ongoing legal process."
All 11 suspects have been formally charged in a federal indictment that was unsealed on July 7, more than a week after the FBI announced their arrests.
The indictment charged all the defendants with conspiring to act as secret agents and also charged nine of them with conspiracy to commit money laundering. It also demands that those accused of money laundering return any assets used in the offense.
with agency reports