In the diplomatic fallout over the murder of a Georgian man in Berlin, Russian President Vladimir Putin threatened to respond in kind to Germany's move to expel two Russian diplomats.

"There are unwritten laws in such cases: You expelled our diplomats, we expel yours," Putin said at a press conference on Monday night following talks on the Ukraine conflict.

Germany expelled the Russian Embassy employees last Wednesday over Moscow's failure to cooperate in the murder investigation. Federal prosecutors said that evidence indicated Russian or Chechen state involvement in the murder.

Although Putin denied any involvement, he described the murdered man as a "bandit" and killer. He said that Russia's requests to extradite him had not been heeded.

He added, however, that Moscow was ready to assist in the investigation and "do everything to help our German colleagues." Putin also denied that there was a diplomatic "crisis" between the two countries.

German Chancellor Angela Merkel said she had raised the issue with Putin during their bilateral talks in Paris, urging Moscow to cooperate.

"I expect that the Russian side will provide us with its information," Merkel said. "In any case, I think that would be good."

Read more: Did Russian intelligence hire a criminal to execute a Chechen dissident in Berlin?

Political murders 'cannot be tolerated'

Bijan Djir-Sarai, foreign policy spokesman for Germany's business-friendly Free Democrats (FDP), said he expected further clarification from both Russia and Germany — including the source of Berlin's "suspicion that ultimately led to the expulsion of the two diplomats."

"Political murders on EU soil cannot be tolerated under any circumstances," Djir-Sarai said in an interview with DW. "The Russian government must now back up its words with actions to help the chief prosecutor solve this murder."

Read more: German defense minister calls out Russia after Berlin murder

Jan Korte of the socialist Left party praised the government's handling of the case, but stressed that the German-Russian relationship could do with improvement. He told DW there should be "reasonable cooperation," especially given Germany's historical responsibility — a reference to Nazi Germany's invasion of the Soviet Union during World War II and to the Red Army's role in defeating Nazi forces.

What is the case?

In late August, 40-year-old Zelimkhan Khangoshvili was shot in an "execution-style" killing in a Berlin park. The suspect in the case carried out the shooting on a bicycle in broad daylight — shooting the victim in the head and chest.

Khangoshvili was an asylum-seeker of Chechen descent from Georgia. He fought against the Russians as a separatist during the Second Chechen War from 1999 to 2009. After the war, he reportedly worked in both Ukraine and Georgia against Russian interests.

He applied for asylum in Germany in 2016 following multiple attempts on his life in Georgia. However, his asylum application was denied and he was slated for deportation.

On Wednesday, German federal prosecutors said that there was "sufficient evidence" to indicate that the man's murder may have been carried out on Russia's behalf. The expulsions of the diplomats were announced the same day.

Russia condemned the move as "unfriendly" and said that suspicions of Russian state involvement were "baseless."

Marcel Fürstenau contributed to this report.

nm,rs/dr  (dpa, Reuters, AFP)

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