BERLIN (AFP) - A German court on Wednesday (Oct 7) put a Russian man on trial over the assassination of a former Chechen commander in a Berlin park allegedly on Moscow's orders, a case that risks worsening acrimonious ties between Germany and Russia.

Vadim K., also known as Vadim S., stands accused of gunning down a Georgian national identified by German authorities as 40-year-old Tornike K., in Kleiner Tiergarten park on Aug 23 last year.

The 55-year-old accused has so far stayed mum over the case, but German prosecutors, who do not release the full names of suspects, have alleged that Russia ordered the killing.

The brazen murder in the heart of the German capital appeared to be a tipping point for Chancellor Angela Merkel, who said in May that the killing "disrupts a cooperation of trust" between Berlin and Moscow.

The German leader has always stressed the importance of keeping dialogue open with Russian President Vladimir Putin, but she has sharpened her tone in recent months.

The trial also comes with Europe already outraged over the poisoning in August of Kremlin critic Alexei Navalny, who is receiving treatment in the German capital.

Germany has said that tests it carried out showed the 44-year-old was poisoned with the Soviet-era deadly nerve agent Novichok - a finding corroborated by France and Sweden.

Russia denies all allegations over the Berlin murder and Mr Navalny's poisoning.

But Dr Merkel's government has not ruled out pushing for sanctions from the European Union following the Novichok attack.

POSED AS A TOURIST

Given the high stakes, Wednesday's trial will likely be closely scrutinised for details pointing to Moscow's alleged involvement.

Investigative website Bellingcat named the suspect as Vadim Krasikov, who grew up in Kazakhstan when it was part of the Soviet Union before moving to the Russian region of Siberia.

He received training from Russia's FSB intelligence service and was part of its elite squad, the website said.

Days before the August 2019 killing, he had posed as a tourist, visiting sights in Paris including the Eiffel Tower before travelling to Warsaw, according to a report in Der Spiegel weekly.

He also toured the Polish capital before vanishing on Aug 22, without checking out from his hotel, the report said.

A day later, riding a bicycle in Berlin's Kleiner Tiergarten park, the suspect approached the victim from behind, firing a Glock 26 pistol equipped with a silencer at the side of Mr Tornike K.'s torso, German prosecutors said.

After the victim fell to the ground, the accused fired another two shots at his head that killed the Georgian on the spot.

He was seen throwing a bag into the nearby Spree river from where police divers later recovered the Glock handgun, a wig and a bicycle, according to the prosecutors.

The suspect was arrested after the killing, which took place just minutes away from the chancellery and the German parliament.

Investigators later found his mobile phone and a return flight ticket for Moscow on Aug 25 in his hotel room in Warsaw, Spiegel reported.

'VERY CRUEL'

Mr Putin had described the victim as a "fighter, very cruel and bloody" who had joined separatists against Russian forces in the Caucasus and also been involved in bombing attacks on the Moscow metro.

Moscow also said it had been seeking his extradition.

Named as Zelimkhan Khangoshvili by German media, the victim had survived two assassination attempts in Georgia.

Following that, he sought asylum in Germany and had spent the past years in the country.

Both the killing and Mr Navalny's poisoning have been likened to the poisoning of former Russian agent Sergei Skripal in Britain in 2018, also widely blamed on Russian intelligence.

Furious over the killing in a busy park in broad daylight, Berlin expelled two Russian diplomats, sparking a tit-for-tat reaction from Moscow.

Russia has for years drawn the ire of Western powers, from annexing Ukraine's Crimea to meddling in elections and backing President Bashar al-Assad's government in Syria.

Dr Merkel this year also revealed that she was the target of "outrageous" hacking attempts by Russia.

If convicted, the suspect faces life in jail.