Germany is reportedly to open a formal investigation into suspicions Russia was behind the killing of a man in central Berlin earlier this year.

In what has been called a “second Skripal case”, prosecutors are said to believe Moscow ordered the assassination of Zelimkhan Khangoshvili in August.

German authorities have yet to publicly comment, but according to local press reports they are convinced a Russian national held over the killing was acting on behalf of the Kremlin.

The case is reportedly set to be transferred from Berlin to federal prosecutors who are responsible for crimes involving espionage and national security.

“We have evidence that a foreign intelligence agency was behind it and therefore the case is going to be taken over by the federal prosecutor this week,” the Reuters news agency quoted an unnamed security source as saying.

The development looks certain to worsen already strained relations between Russia and the West.

Khangoshvili, a 40-year-old Georgian who fought against Russia in Chechnya and had links with Georgian intelligence, was shot dead from behind by a cyclist in broad daylight in Berlin’s Kleiner Tiergarten park in August.

The suspected killer escaped but was captured by police attempting to dispose of a gun believed to be the murder weapon in the nearby river Spree.