Simon Otrovsky, a journalist who worked alongside Babchenko, tweeted on Wednesday: 'While I am very happy Arkady is alive I am also angry and confused because my fellow reporters and I spent yesterday posting and reading memories we shared of him and feeling very down and out'. Babchenko reappeared alive on Wednesday less than 24 hours after he was believed to have been gunned down in Kiev.
His reported murder sparked a war of words between Ukraine and Russian Federation.
The Putin government has accused Ukraine of "fanning anti-Russian hysteria".
Babchenko said he was not allowed to go into the details of his false death.
"I've promised to die when I'm 96, having danced on Putin's grave and taking a selfie while standing on an Abrams [tank] on Tverskoi Boulevard" in Moscow", he wrote.
Russia's foreign ministry expressed relief at Babchenko being alive. He described his Chechen experiences in a book, "One Soldier's War in Chechnya". He covered such conflicts as the 2008 Russia-Georgia war over South Ossetia and the 2010 inter-ethnic violence in southern Kyrgyzstan for Novaya Gazeta and other publications.
'Murdered' Russian Journalist Arkady Babchenko Turns Up at Press Conference
Gritsak said the agency had collected proof his assassination had been ordered by the Russian security services. Babchenko told the news conference he had previously fled Russian Federation after receiving death threats.
In recent years, he became increasingly alienated from Moscow journalists critical of the Kremlin. As a journalist, he criticized his country's annexation of Crimea and the Kremlin's support for separatist Ukrainian rebels. Russia's high commissioner for human rights, Tatiana Moskalkova, promised to address Ukrainian authorities, urging them to pay special attention to the investigation of the journalist's murder.
Babchenko left Russian Federation in February 2017, saying he was receiving threats and concerned he might be jailed.
But in Moscow, Russia's Investigative Committee distanced the Kremlin from the killing - saying it had launched its own criminal investigation into Babchenko's death. He moved to Kiev after living in the Czech Republic and Israel. In Kiev, he has been a television host on Crimean Tatar network ATR. Known for his caustic style and earthy language, Babchenko endlessly promoted doom-and-gloom scenarios for Russian Federation under Putin.
"Arkady knew what war was about, took part in it but always hated it viscerally", the award-winning newspaper said in an editorial.
Before ushering Mr Babchenko into the room, Mr Gritsak said investigators had identified a Ukrainian citizen who was allegedly paid 40,000 dollars (£30,000) by Russian security services to organise and carry out the hit.
"Everything is over from yesterday", Babchenko said.