Ukraine's security chief now says his organization planned to have a prominent Russian war correspondent and Kremlin critic fake his own death as part of a ruse to save the reporter's life.

The journalist Arkady Babchenko  - thought dead - stunned reporters when he appeared alive and well Wednesday, one day after he had been reportedly been shot and killed in the stairwell of his Kyiv apartment.

Vasyl Hrytsak of Ukraine's Security Service, SBU, stood alongside Babchenko at Wednesday's television briefing as he recounted events leading up to the foiled assassination attempt, explaining the fictitious reports of his death were part of an SBU sting operation that had been prepared for two months.

The operation began with a tip from an anonymous source who said an unidentified Ukrainian national had been inquiring about buying weapons for a contract assassination in Kyiv, which triggered the SBU probe. Officials said he had been asked to find and hire someone to carry out the contract killing.

During the negotiations, Hrytsak said, the man claimed Russia's Secret Service had offered him $40,000 to organize and carry out the hit. He said the suspect was a former separatist fighter who had fought in eastern Ukraine.

SBU investigators then recruited Babchenko into the sting operation designed to catch Russian agents in the act of conducting an extrajudicial killing on foreign soil.

Investigators said the intermediary who had been tasked with hiring the gunman was in custody, and officials said they had additional hard evidence linking Russia's secret service to the assassination plot, though they did yet want to unveil that evidence.

Addressing reporters, Babchenko told his family he was sorry for faking his own death.

Russian journalist Arkady Babchenko reacts during
Russian journalist Arkady Babchenko reacts during a news conference at the Ukrainian Security Service on May 30, 2018.

"I'd like to apologize for everything you've had to go through," he said. "I've been at the funeral of many friends and colleagues, and I know this nauseous feeling. Sorry for imposing this upon you, but there was no other way.

"Special apologies to my wife for the hell she's been through these two days," he added. "Olya, excuse me, please, but there was no other option."

Read: Transcript of Babchenko's remarks

Police reports that followed initial reports of the shooting say it was Babchenko's wife who discovered him lying in a pool of blood at the entry of their Kyiv apartment.

It is not clear whether his wife was involved in the sting.

"As far as I know, this operation was prepared for two months. A result of that was this special operation," Babchenko told the briefing." They saved my life. I want to say thanks. Larger terrorist attacks were prevented."

Tuesday's news of the shooting shocked the Ukrainian capital, prompting Kyiv and Moscow officials to blame each for the reporter's death.

Ukrainian police officers guard as flowers are pla
Ukrainian police officers guard as flowers are placed near the entrance to a house where Russian journalist Arkady Babchenko lives in Kyiv, Ukraine, May 29, 2018.

Ukrainian Prime Minister Volodymyr Groysman suggested Russia had orchestrated the killing, while Kremlin spokesman Dmitry Peskov rejected that claim and condemned Ukraine as an unsafe place for journalists.

Russian Foreign Ministry spokeswoman Maria Zakharova said after Babchenko's reappearance Wednesday that officials in Moscow were glad Babchenko was still alive.

But Zakharova said Ukrainian officials had circulated a false story as "propaganda."

Kyiv police and officials from Ukraine's Interior Ministry had announced on Tuesday Babchenko had died in an ambulance on the way to a hospital after being shot in the back at his home in Kyiv, where he has lived in exile since August 2017.

News of the 41-year-old's reported death had shocked colleagues and added to tension between Moscow and Kyiv, whose ties have been badly damaged by Russia's seizure of Crimea and backing for separatist militants in a devastating war in eastern Ukraine.

(This story originated in VOA's Ukrainian Service Some reporting by AP and RFE)