Russian opposition journalist Arkady Babchenko, who was shot dead at his flat in Kiev last night

The Kremlin has denied claims from Ukraine that it was behind the killing of a prominent critic of Vladimir Putin in Kiev, branding the allegations the “height of cynicism”.

Arkady Babchenko, a 41-year-old Russian war correspondent and author, was gunned down as he opened the door of his flat in Kiev last night by an assassin who had been waiting for him in a stairwell, Ukrainian officials said.

His wife called emergency services after discovering him lying in a pool of blood, but he died in an ambulance.

Volodymyr Groysman, the Ukrainian prime minister, blamed President Putin’s “totalitarian machine” for Mr Babchenko’s murder. Moscow said that it was launching its own investigation into the shooting and criticised what it said was Kiev’s failure to punish