Putin's former defense chief threatened with more severe charges MOSCOW (Reuters) - A former Russian defense minister was charged with negligence on Friday and threatened with tougher charges in a case seen as a test of President Vladimir Putin's stated determination to fight corruption but also a sign of Kremlin infighting. Putin fired Anatoly Serdyukov, his longtime defense chief, in November 2012 after a fraud scandal involving ministry property erupted involving a female subordinate of Serdyukov who was also his neighbor. But he has so far been treated solely as a witness in that case. Last week, the federal Investigative Committee announced an inquiry over allegations that Serdyukov ordered troops to build a road to a luxury resort in southern Russia, causing a loss to the state of more than 56 million roubles ($1.7 million). He was charged on Friday with negligence, punishable by up to three months in jail, or a year of "corrective work" or community service - far less severe punishments than those faced by those charged in the fraud scandal. Final charges will be brought later "and they could quite possibly be expanded," Investigative Committee spokesman Vladimir Markin said, according to the Interfax news agency. He said Serdyukov had been questioned and denied wrongdoing. In power since 2000, Putin has repeatedly pledged to fight the corruption that has hampered post-Soviet Russia's development and discouraged investment, but critics say the problem has only worsened under his rule. Opponents accuse the authorities of using allegations of corruption as a tool against rivals in business and politics. Serdyukov is one of the highest-ranking former officials to be prosecuted over allegations of graft, but government critics say the light punishment he could now face under the negligence charge suggest his close Kremlin ties give him some protection. Putin brought in Serdyukov in 2007 to conduct reforms resisted by the Russian military brass. He was seen as a loyal courtier tied to the president by his marriage to the daughter of Viktor Zubkov, a Putin ally and former prime minister. But his power and grip on financial flows made him unpopular with others in Putin's circle vying for influence over the armed forces and defense industry, the beneficiaries of a plan to spend 23 trillion roubles ($700 billion) by 2020 to upgrade the military. $1 = 32.7363 Russian roubles Writing by Steve Gutterman; Editing by Mark Heinrich