President Viktor Yushchenko appointed as an adviser on Monday a key figure in the "Orange Revolution" whose accusations of corruption a year ago brought down the pro-Western leader's first liberal government, according to Reuters. A presidential decree said Oleksander Zinchenko would act as an adviser but gave no details on his responsibilities. Zinchenko became secretary of state -- chief of staff -- after overseeing Yushchenko's 2004 presidential election campaign which eventually culminated in a victory over Viktor Yanukovich in the re-run of a rigged poll. In September 2005, Zinchenko abruptly resigned and accused key figures in the presidential administration of corruption. His comments unleashed a wave of accusations of corruption directed at supporters and detractors of Yulia Tymoshenko, Yushchenko's fiery first prime minister. Within a week, the president had fired Tymoshenko and her cabinet as well as her most strident rival in the administration. The split in "orange" ranks generated mass disillusion among liberals, magnified by Yanukovich's comeback in last March's parliamentary election, when his Regions Party came first. Yanukovich eventually became prime minister in August. Tymoshenko, her chances of becoming prime minister again scuttled by defections in "orange" ranks is in opposition. Zinchenko, 49, mostly stayed out of politics after his resignation. With his powers reduced by constitutional change and challenged by Yanukovich on key issues, the president has made major changes in his administration line-up in recent weeks.