The two Russian spies reportedly arrested in Germany were probably retired veterans from the Soviet era who were only used on rare occasions, a Moscow foreign intelligence official said on Monday. Der Spiegel first reported that the couple had begun spying in Germany for the former Soviet KGB before being arrested last week in the first incident of its kind since the Cold War. Focus magazine separately said the pair may have had ties to an exposed Russian sleeper cell network in the United States that included the spy-turned-celebrity Anna Chapman. The German prosecutor\'s office only confirmed the arrest of two people on espionage charges without revealing their nationalities or the countries for which they allegedly worked. Der Spiegel identified them as 51-year-olds Andreas and Heirdrun A. and the Kommersant business daily reported their last name as Anschlag. The news broke just a month after Russia\'s most famous retired spy Vladimir Putin -- a man who served in Germany before becoming president and now prime minister -- announced plans to return to the Kremlin in next year\'s elections. Russian official greeted the reports with silence but one SVR foreign intelligence agent said the couple was probably a part of a retired network of spies Moscow has kept in Europe since Soviet times. \"What we are talking about is not espionage activity,\" the unnamed Russian intelligence agent told the Izvestia daily. He added that such retirees were often used as \"mailboxes\" by Moscow for relaying sensitive information in special cases. \"They are already retired, they have families -- and nevertheless, now and then, they transmit and receive information. Sort of like a \'mailbox\' -- we do not leave them behind,\" the Russian agent said.