Fears are mounting for Paul Whelan, the former U.S. Marine seized last month in a Moscow hotel after being accused of espionage. Western intelligence officers and analysts fear he may remain in detention in Russia for a long time and are casting doubt on the likelihood of a spy exchange.Kremlin officials are dismissing the idea he’d be a candidate for a prisoner swap. Their U.S. counterparts say there can’t be any kind of exchange, as he’s not a spy. Kremlin officials Wednesday dismissed a claim by British Foreign Secretary Jeremy Hunt that Russia might use the former Canadian-born U.S. citizen as a pawn in a diplomatic game.Kremlin spokesman Dmitry Peskov told reporters, “In Russia, we never use people as pawns in diplomatic games. In Russia, we conduct counterintelligence activity against those suspected of espionage. That is done regularly.”Hunt last week said the British government was “extremely worried” about the well-being of 48-year-old Whelan, who also holds British citizenship, as well as Irish and Canadian passports, suggesting the Russians might try to use him as leverage for the release of Russia’s Maria Butina, who pleaded guilty to infiltrating America’s conservative political movement as a Kremlin-directed agent. Butina was convicted of acting as a foreign agent in the United States. Whelan was arrested Dec. 28 in Moscow. According to the Russian Federal Security Service (FSB), he was detained while “on a spy mission” and had been caught “during an act of espionage.” The Washington Post reported Whelan was arrested in his room at the Metropol Hotel in Moscow after he had accepted from an unidentified man a flash drive containing a list of employees for a clandestine Russian agency.Earlier this month, U.S. Ambassador to Russia Jon Huntsman was allowed to visit Whelan, who reportedly is being held at the notorious Lefortovo prison, which was used during the purges of the 1930s by Josef Stalin’s NKVD agents and which once housed dissidents such as writer and historian Alexander Solzhenitsyn.Whelan’s family says he’s innocent and was in Russia, which he has visited several times, for a wedding. Speaking to Euronews television this week, his brother, David, also worried about the length of time he may be held.“It clearly could take months, and unfortunately, maybe even years before we get him home,” he said.Whelan could receive a 20-year jail term if he is convicted of espionage. Comparisons with 1986 caseAnalysts and former intelligence officials are comparing Whelan’s case with that of journalist Nick Daniloff, who in 1986 was arrested by the then-KGB and accused of espionage after having been handed an unsolicited package of confidential documents.The Reagan administration said the Soviets arrested Daniloff without cause in retaliation for the arrest three days earlier of Gennadi Zakharov, a physicist at the Soviet U.N. Mission in New York. Zakharov had received classified documents about U.S. Air Force jet engines.After 13 days and intense diplomacy, Daniloff was allowed to leave the Soviet Union without charge, along with Soviet dissident Yuri Orlov. Zakharov was permitted to leave the U.S. But the affair also triggered rounds of expulsions by both sides of dozens of diplomats and suspected spies.The time Whelan spends in jail may not be as brief, some observers fear. U.S. intelligence officials say they would be loath to agree to a swap for a self-confessed Kremlin agent such as Butina for an apparently innocent American, as this could invite the Russians to organize other setups of U.S. civilians, creating an open season.Ned Price, a former Obama administration State Department official, said he thinks the Kremlin may be seeking to swap Whelan for Butina. “The Russians may calculate that Whelan, a military veteran who has said positive things about President Donald Trump on Russian social media, constitutes the perfect quo for their quid,” he wrote in an opinion article.Former U.S. intelligence officials say it is highly unlikely that Whelan, who has had a checkered past and left the U.S. Marines with a dishonorable discharge, and was found guilty of attempting to steal $10,000 worth of currency from the U.S. government while deployed to Iraq in 2006, could have been working for a clandestine U.S. agency.The picture that has emerged of Whelan is complex. Since 2007, he has traveled regularly to Russia both for pleasure and business. He works in corporate security for the automotive industry. He has a fascination for Russia, was trying to learn the language and had an active profile on the Russian social media platform VKontakte.The Whelan case could be further complicated by the arrest on the Northern Mariana Islands on Dec. 29 of Russian citizen Dmitry Makarenko by U.S. authorities.Makarenko was moved to Florida after being detained by FBI officers allegedly for conspiring with another man to export U.S. defense articles, including night-vision scopes, to Russia without U.S. approval.Kremlin officials have accused the U.S. of detaining Makarenko in retaliation for the arrest of Whelan, but the case against Makarenko goes back to 2017, according to court papers filed in the U.S. District Court for the Southern District of Florida.