BERLIN:Germany has transmitted to Russia transcripts of interviews with Alexei Navalny as part of its response to Moscow's request for assistance in its investigation into the poisoning of the Kremlin critic, Berlin said Saturday.

Navalny was evacuated to Berlin in late August for treatment after he fell violently ill on a flight from Siberia to Moscow.

Tests carried out by Western countries including Germany have concluded that he was poisoned by the Soviet-era nerve agent Novichok.

He has said he will return to Russia on Sunday, flying with Pobeda -- Aeroflot's low-cost subsidiary whose name means "Victory" in Russian.

Germany's justice ministry said it "responded yesterday to the four requests for legal assistance from the prosecution office of Russia in connection to the murder attempt on Alexei Navalny in Russia".

Police investigators had questioned Navalny, who "provided extensive answers to questions sent through by the Russian prosecutor", said a spokesman for the German justice ministry.

The transcripts were transmitted to Moscow, he added.

"The government assumes that the Russian government will now take all necessary steps to clear up this crime against Mr Navalny," said the spokesman.

"All the information necessary in criminal investigations like blood and tissue samples, clothing pieces, are in, are available in Russia," he said.

Navalny has accused Russia's main security agency, the Federal Security Service (FSB), of poisoning him on the orders of President Vladimir Putin.

Russian authorities have repeatedly denied any involvement and refused to investigate the case.