Remarkably, Mr Babchenko showed up at the news conference and thanked everyone who was mourning his death.
"I am sorry, but there were no options here", Babchenko said at the presser.
Police said the Kremlin critic had died of multiple gunshots wounds to his back, with Kiev's police chief claiming Babchencko's "professional activities" as a journalist were a factor in his apparent murder.
Babchenko is a well-known war correspondent in Russian Federation.
Ukrainian Prime Minister Volodymyr Groysman said in a social media posting late on Tuesday he was convinced what he called "the Russian totalitarian machine" had not forgiven Babchenko for what Groysman called his honesty.
At a news conference in Kiev, Babchenko told a stunned media: "Special apologies to my wife, Olechka".More news: Game 1 of Stanley Cup Final produces record TV ratings
After moving to Ukraine from Russian Federation in February 2017, Babchenko continued to receive death threats, but reportedly did not take them seriously, according to someone who knew him.
Vasily Gritsak, head of the Ukrainian security service, revealed to the press Wednesday afternoon that Babchenko's death was an elaborate hoax that had been planned for months. The Russian ministry said that Ukraine "deceived the entire worldwide community" with the ruse, which was now clearly exposed as a publicity stunt meant to smear Russia. He said he was approached by the Ukrainian Security Service, or SBU, a month ago.
No stranger to death, Babchenko served in the Russian army during Chechnya's two wars for independence, after which he wrote a powerful memoir about the everyday brutality of conflict before turning to journalism, writing about war for a range of Russian publications.
Today's official narrative from the regime is that Arkady Babchenko is alive and well having not been shot or been the victim of any altercation. Babchenko had left Russian Federation for Ukraine in February 2017 because he feared for his life.
Moscow, which has been at odds with Kiev since a 2014 popular revolt in Ukraine that toppled a Russian-backed government in favour of a pro-Western one, described such allegations as part of an anti-Russian smear campaign.
Ukrainian officials led by Prime Minister Volodymyr Groysman accused Russian Federation of being behind the killing of the Kremlin critic, a charge that Moscow batted back.