Germany renews call for "Russia to make a declaration on the events" of the Navalny case after three European laboratories independently identified a military nerve agent poisoned Alexey Navalny.
Specialist labs in France and Sweden have confirmed that Russian opposition leader Alexey Navalny was poisoned with the Soviet-era nerve agent Novichok.
German government's spokesman Steffen Seibert said on Monday that samples taken from the Russian opposition politician, who is currently being treated in Berlin, had also been sent to the Organisation for the Prevention of Chemical Weapons (OPCW) in The Hague for tests in their labs.
A German military laboratory previously confirmed the substance in his samples.
Army doctors at Berlin's Charite hospital, to which Navalny was evacuated after taking ill on a flight over Siberia last month, were the first to say he had been poisoned with Novichok. Navalny awoke from a coma last week.
"Independently of the OPCW's investigations, three laboratories have now independently identified a military nerve agent as the cause of Mr Navalny's poisoning," Seibert said.
Russia says it has seen no evidence that Navalny was poisoned.
The poisoning has brought tensions between Russia and Germany to new heights, fuelling calls for the Nord Stream 2 pipeline, a Kremlin flagship project to bring Russian gas direct to Germany under the Baltic Sea, to be scrapped.
On the basis of the findings by the three European laboratories, however, Seibert said Germany was "renewing its call for Russia to make a declaration on the events" of the Navalny case.
"We are in close contact with our European partners about further steps," he added.
Kremlin slams attempts to blame Russia
Navalny has now emerged from a medically induced coma and is reacting to speech, Berlin's Charite hospital has said.
The Kremlin has denounced attempts to blame the Russian state for the poisoning as "absurd" and said it wants to know what happened.
Western politicians have said the incident appears likely to have been state-ordered and urged Moscow to prove its lack of involvement.
Navalny's associates believe the use of Novichok shows only the Russian state could be responsible.
The case has prompted international calls for Russia to carry out a transparent investigation or risk sanctions, but the country has not opened a criminal investigation.
Kremlin spokesman Dmitry Peskov said on Friday that Russia rejected "when other countries dictate to us what legal procedures we should start and when".
He insisted Russia "de facto" is probing the incident, but cannot open a criminal case "on the basis of tests by the German side, especially when carried out in German military labs."
Russian authorities want to question Navalny at his Berlin hospital, with Siberian transport police, who have been retracing Navalny's movements, saying on Friday that Russia would be preparing a request for its officers and an "expert" to shadow German investigators.