German Foreign Minister Heiko Maas said on Wednesday that the latest media reports on the poisoning of Russian dissident Alexei Navalny confirm the German government's assessment that Russia was behind it.

Reports that Navalny had been poisoned with the chemical nerve agent Novichok, are "neither new nor surprising," Maas told dpa.

"The fact that this has now been reappraised and corroborated by journalistic research is a confirmation for us," he added.

Pointing to the sanctions already imposed by the EU against those it holds politically responsible for Navalny's poisoning, Maas said he did not expect the reports to prompt further consequences.

Maas' comments come the day after Russia retaliated against the sanctions by banning entry to German government representatives.

"This Russian reaction follows a familiar pattern, but it is not a contribution to the solution," Maas said.

"After all, the Navalny case is not about a bilateral dispute. It's about a serious violation of the international ban on chemical weapons in Russia," he added.

In a report published this week by the medical journal The Lancet, a team from Germany's Charite hospital in Berlin, where Navalny was treated, said a Novichok poison was detected in his bloodstream after his admission to the hospital in August.

Navalny became seriously ill while on a domestic flight in Russia on Aug. 20 and was initially treated at a hospital in the Siberian city of Omsk before being evacuated to Berlin.