Kremlin opponent and exiled businessman Boris Berezovsky revealed Wednesday that Scotland Yard had warned him last month about an assassination attempt on his life.
Scotland Yard would neither confirm nor refute his claims.
During a press conference in London, Berezovsky alleged that on June 16 Scotland Yard had alerted him about a plot to murder him and advised him to leave the country for a week until the threat was resolved.
Scotland Yard would say only that "on the 21st of June, a man was arrested in central London on suspicion of conspiracy to murder." The man was "later released on the 23rd of June without charge into the custody of the Immigration Service."
Speaking to ABC News, a Scotland Yard spokesman refused to confirm if this arrest was connected to Berezovsky's allegations.
The Russian billionaire said that the suspect was eventually deported to Russia, but when ABC News contacted the Home Office, its spokesperson refused to comment on the matter.
This is the latest in a long string of accusations leveled by Berezovsky against the Kremlin.
Last year, following the suspicious death of former KGB agent Alexander Litvinenko, Berezovsky openly accused Russian President Vladimir Putin of personal involvement in the ex-spy's murder.
On his deathbed, Litvinenko himself blamed Putin for his death by poisoning from the radioactive substance polonium-210.
Wednesday, in an interview with ABC News, Berezovsky described himself as "maybe the most important witness of Litvinenko's murder," adding that those "who killed Litvinenko got [the] order from Putin. Yes, Putin organized this murder."
Discussing his own brush with a possible assassination attempt, the Russian billionaire told ABC News that he was informed three months ago that "someone from Russia" would try to kill him.
The alleged murderer would "do it absolutely openly," Berezovsky said, adding that the plan was to "present this story as a business story, that we argued [over money]."
"I didn't pay too much attention to that, but I informed Scotland Yard," Berezovsky said.
Then, some months later, according to the Russian exile, Scotland Yard contacted him and said that "someone who knows you, came here with a plot to kill you and you should leave the country immediately."
Recalling the day, he said, "It was the birthday of Alexander Litvinenko's wife, and I wanted to spend time with her, but nevertheless, I was not able to stay and I left the country. In a week's time, they called me and said, 'We cleaned the situation, you may return back.'"
But with Scotland Yard refusing to confirm any of this, some claim that Wednesday's press conference was yet another example of the Russian émigré's efforts to show up the Kremlin at any cost, whether what he said was true or not.
When ABC News asked him if he had any independent proof of the alleged assassination attempt, he bristled: "I answer to your questions, and that's it. It's not a story which [is] created by me, the story [is] created by you journalists."
Softening a little, he said that it's a "pleasure to answer to your questions, but [it's] your choice to trust me or not."
The Kremlin, for one, does not trust the former math professor, who made a killing in secondhand cars after the fall of communism.
Since leaving Russia in 2001, Berezovsky claims to have spent "between $300 [million] to $400 million" funding opposition groups in the country.
Russia has long demanded his extradition to Moscow, where Berezovsky is currently being tried in absentia on charges of embezzlement. Britain has refused to comply.
Meanwhile, the Kremlin has refused to hand over Andrei Lugovoy, the chief suspect in the Litvinenko poisoning, to Britain.
In response to this refusal, Britain expelled four Russian diplomats Monday.
The Russian ambassador, Yury Viktorovich Fedotov, told the BBC that the timing of Berezovsky's revelations was "quite noteworthy," adding that this might be part of "an attempt to vindicate in the eyes of the British public the line taken by Whitehall [the British government's position]."
At his press conference, Berezosky denied any connection between his recent allegations and the ongoing clash between the British and Russian governments.
But, in an interview with ABC News, he didn't mince any words, saying that the Russian state tries "to protect not Lugovoy, but Putin himself."
"I am sure," he continued, "that Putin is in trouble, that he [is] really afraid [after] what happened. He didn't expect that polonium could be discovered."