Prominent Russian opposition leader Alexei Navalny called out German former-Chancellor Gerhard Schröder over his close relationship with Russian President Vladimir Putin.

"Gerhard Schröder is paid by Putin," Navalny told Germany's daily Bild newspaper in an interview published on Wednesday. "If he now tries to deny this poison attack as well that's really very disappointing."

Read more: Alexei Navalny blames Vladimir Putin for poisoning

Putin's 'errand boy'

Despite evidence from German scientists that Navalny was poisoned using Novichok, Schröder said there were no "hard facts" on who is responsible.

"He's still the former chancellor of the most powerful country in Europe," Navalny said. "Now he's Putin's errand boy, he protects murderers."

In August, Navalny fell ill on a plane. After initial treatment in a Siberian hospital, he was medically evacuated to Berlin's Charite hospital.

A German military laboratory concluded that his illness was caused by poisoning from a Soviet-designed nerve agent Novichok. Laboratories in Sweden and France confirmed the finding. Russia has denied responsibility for Navalny's condition. 

Schröder has a close relationship with Putin, going back to his time in office, once agreeing that the Russian leader a "flawless democrat." The former German leader also holds top spots in Russian energy businesses. He is the chairman of the board of the Nord Stream pipeline, as well as the chairman of the pipeline project Nord Stream 2. 

Calls for EU action

Navalny has also called on the European Union to take strict action against Russian oligarchs close to the government, adding that in Russia there is "not even an attempt to make it look like they are investigating" his case.

"Sanctions against the whole country don't work," Navalny said. "The most important thing is to impose entry bans on profiteers of the regime and freeze their assets.

"They embezzle money, steal billions and at the weekend they fly to Berlin or London, buy expensive apartments and sit in cafes," he added.

Berlin to talk sanctions

On Wednesday, Germany's Foreign Minister Heiko Maas said Russia would need to explain the poisoning. If not, Maas said there would be no way to avoid "targeted and appropriate sanctions against those responsible."

"We are going to discuss the reactions with our European partners" in the coming days, Maas told German lawmakers.

When asked about the possible involvement of the Russian state in the Novichok poisoning, Maas said that "no other explanation is plausible" from the German point of view.

However, Maas refused to comment Navalny's accusations against Schröder, either personally or in the name of the German government. Maas is a member of the center-left SPD, a party once led by Schröder.

Meanwhile, senior German conservative Jürgen Hardt joined the criticism against Schröder, saying that his position in the Navalny case "fills many in Germany with shame."

Hardt, who is the ranking CDU lawmaker on foreign policy, also said the EU should close ranks over the poisoning.

"It would appear most effective to freeze the enormous assets of Putin's nomenclature abroad," he said.

see,dj/sms (dpa, Reuters)