Russia announced Thursday it had launched a police "check" into opposition leader Alexei Navalny's illness and asked German medics treating him to share his medical records while the Kremlin continued to insist there were no grounds for a criminal probe.
The German doctors have said tests on the 44-year-old politician and anti-corruption campaigner indicate that he was poisoned, and his allies have pointed the finger of blame at President Vladimir Putin.
In an interview on state-controlled television on Thursday, Putin made no mention of the case.
Prosecutors said they had "no evidence" of a deliberate crime committed against Navalny and requested that German medics hand over "the evidence for the initial diagnoses they gave" including test results.
- Suspected nerve agent -
Navalny fell ill on a plane to Moscow from the Siberian city of Tomsk on Thursday. He spent two days in a Russian clinic in a coma before being transferred to Berlin's Charite hospital.
Medics there said on Monday they do not know the exact substance involved but that Navalny was apparently poisoned with a substance that inhibits the cholinesterase enzyme, a feature of nerve agents.
Navalny's allies say he may have been poisoned by a cup of tea he drank at Tomsk airport.
International calls have been mounting for an independent probe into the case, but Kremlin spokesman Dmitry Peskov on Thursday dismissed the police check as routine, saying: "there is no basis for an investigation".
"Nothing has changed, we still don't have any understanding of what caused the state the sick man is now in," he told journalists.
Transport police in Siberia said they had started "a pre-investigation check" into what led to Navalny's hospitalisation in the Siberian city of Omsk to establish "all the circumstances" and decide whether to open a criminal probe.
The police action appears to be a low-level response after Navalny's allies asked for an investigation into an attempted assassination of a public figure.
Police do such checks to determine whether a crime has been committed.
Navalny's spokeswoman Kira Yarmysh tweeted that they had not been informed of the police check.
- Hotel room searched -
"Open a criminal case!" tweeted Ivan Zhdanov, the director of Navalny's Anti-Corruption Foundation.
Prosecutors said that they began the check on the day Navalny fell ill but did not say whether they plan to launch a criminal probe.
Russian doctors said their tests did not find any trace of poison while they treated Navalny with the same antidote, atropine, that German medics are using.
Police and plain clothed security service agents questioned doctors at the hospital without making any public statements.
Transport police said they searched locations that Navalny visited and his hotel room, apparently referring to where he stayed in Tomsk.
They said they also examined security camera footage and confiscated "more than 100 items that could have value as evidence".
Police said that they did not find any "strong-acting or narcotic substances".
Peskov has repeatedly rejected international calls for a transparent investigation from Western leaders including British Prime Minister Boris Johnson and NATO chief Jens Stoltenberg.
French Foreign Minister Jean-Yves Le Drian said Thursday he did not understand why Russia did not opt for transparency, which would be "to their credit."
Peskov has argued it is not possible to say that Navalny was poisoned since no toxic substance had been identified.
Putin discussed the case with Italian Prime Minister Giuseppe Conte late Wednesday, the Kremlin said.
Putin rejected "rushed and groundless accusations" but said that Russia had an interest in a "scrupulous and objective investigation of all the circumstances."
Unusually, the Kremlin statement quoting him referred to Navalny by name, while its practice has been never to do so.
The Russian foreign ministry said Tuesday that international statements alleging deliberate poisoning were "clearly not" in the Russian leadership's interests.