A Russian journalist and opponent of Vladmir Putin was hospitalized Wednesday with severe poisoning, according to his father. Vladimir Kara-Murza Jr., an ally of recently assassinated opposition leader Boris Nemtsov, is suffering from with kidney failure but is expected to improve. “All night we’re diagnosing, first the heart—they wanted to change the valve, then canceled that diagnosis, now they’re searching for some kind of intoxication, then some sort of bleeding,” his father told state-owned RIA News agency. Opposition leaders, including Alexey Navalny, tweeted their support for the activist, who fell ill while at the Russian Legal Information Agency. The poison as not been identified yet, but journalists report that they are awaiting a stomach contents analysis.