A Siberian region is suing one of Russia\'s richest men for tens of millions of dollars in allegedly unpaid taxes, just after he announced he was entering politics, reports said on Saturday. The Lenosibirsk district of the Krasnoyarsk region of central Siberia is seeking two billion rubles (70 million dollars) from billionaire Mikhail Prokhorov, the RIA Novosti news agency and Kommersant daily reported. The move comes just a month after Prokhorov, head of the Onexim investment holding with a reported fortune of $18 billion, unexpectedly announced he was going into politics and planned to lead the Right Cause Party. Prokhorov is registered in the tiny Siberian village of Eruda and pays his taxes there. The local branch of the tax service believes Prokhorov failed to pay taxes due to the Russian state on a transaction in Britain in south Wales in 2008, the deputy head of the regional anti-monopoly service Oleg Kharchenko was quoted by RIA Novosti as saying. \"As the Lenosibirsk tax inspectorate lacks an experienced specialist in the problems of south Welsh tax law, they asked the anti-monopoly service for help,\" he was quoted as saying. A source in the regional tax inspectorate told RIA Novosti that the issue had already gone to court. Prokhorov was quoted on the sidelines of the Saint Petersburg Economic Forum as acknowledging the dispute but expressing confidence that he would win in court. The entry of Prokhorov into politics sent a ripple of excitement through Russia\'s political scene, though cynics pointed out that neither the billionaire nor his party have so far sharply criticised the Kremlin. Kommersant underlined the coincidence of the timing of the case with the headline: \"Prokhorov has now got into real politics.\" Russia\'s former richest man Mikhail Khodorkovsky was arrested in 2003 on suspicion of tax evasion, at a time when he was financing opposition parties. He was convicted twice and is not due for release until 2016.