The widow of Russian dissident Alexei Navalny, who died in prison last week, has surmised that the government there is engaged in a coverup to hide evidence of his likely exposure to Novichok, a nerve agent that has become a signature assassination technique for President Vladimir Putin’s authoritarian regime. “They are now hiding his body, not showing it to his family, not giving it to them, but lying and waiting pitifully for the traces of Putin’s another Novichok to disappear,” she said in a solemn address to the Russian public posted to YouTube on Monday. In her statement, Yulia Navalnaya swore to identify who carried out the killing and promised to continue her late husband’s efforts to defy Putin’s control over the Russian people, according to the independent newspaper The Moscow Times. “Putin not only killed the man called Alexei Navalny, he also wanted to kill our hopes, our freedom, and our future,” she said, noting the brutal conditions he endured while being trapped in a small concrete cell at the IK-3 penal colony in Kharp. The prison is some 1,200 miles northeast of Moscow—an isolated spot within the Arctic Circle that she described as being trapped in an “eternal winter.”