Russian opposition politician Alexei Navalny has been removed from the penal colony where he had been imprisoned since the middle of last year and his current whereabouts are unknown, his allies said on Monday. Navalny aides have been preparing for his expected transfer to a "special regime" colony, the harshest grade in Russia’s prison system, after he was sentenced in August to an additional 19 years in prison on top of 11-1/2 years he was already serving.