OMSK: Doctors have not found any evidence that Russian opposition figure Alexei Navalny was poisoned, the deputy head doctor of the Siberian hospital where he was being treated said Friday.
"So far no poison has been identified in the blood and urine, there is no trace of its presence," Anatoly Kalinichenko told journalists in Omsk.
"The diagnosis of 'poisoning' is still there in the back of our minds, but we do not believe that the patient suffered poisoning," he said.
"We practically have a diagnosis," he said, adding that information had been passed on to Navalny's family.
"The patient's condition is unstable, it is advisable to refuse any transportation," he added, after an air ambulance had arrived following an offer to transport Navalny to Germany for treatment.
Omsk is about 4,200 kilometers (2,500 miles) east of Berlin, roughly a six-hour flight.
"The chief doctor said that Navalny is non-transportable. (His) condition is unstable. Family's decision to transfer him is not enough," Navalny spokeswoman Kira Yarmysh also tweeted.
Yarmysh also said that "the ban on transferring Navalny is needed to stall and wait until the poison in his body can no longer be traced. Yet every hour of stalling creates a threat to his life."
Meanwhile, Navalny's ally Ivan Zhdanov said Friday that police found "a very dangerous substance" in Navalny's system, but officials refuse to disclose which substance it is.
Like many other opposition politicians in Russia, Navalny has been frequently detained by law enforcement and harassed by pro-Kremlin groups.
In 2017, he was attacked by several men who threw antiseptic in his face, damaging an eye.
Last year, Navalny was rushed to a hospital from prison, where he was serving a sentence following an administrative arrest, with what his team said was suspected poisoning.
Doctors said he had a severe allergic attack and discharged him back to prison the following day.
Navalny's Foundation for Fighting Corruption has been exposing graft among government officials, including some at the highest level.
Last month, he had to shut the foundation after a financially devastating lawsuit from Yevgeny Prigozhin, a businessman with close ties to the Kremlin.
The most prominent member of Russia's opposition, Navalny campaigned to challenge President Vladimir Putin in the 2018 presidential election, but was barred from running.
He set up campaign offices across Russia and has been promoting opposition candidates in regional elections, challenging members of Russia's ruling party, United Russia.
Navalny remains in a coma in intensive care after a suspected poisoning his allies link to his political activity.