Britain's senior law and order official said an inquiry into the death of a poisoned ex-KGB spy had expanded overseas, and a United States-based friend of the former agent said he had given police the name of a suspect he believes orchestrated his killing. "The truth is, we have an act of international terrorism on our hands. I happen to believe I know who is behind the death of my friend Sasha (Litvinenko) and the reason for his murder," Yuri Shvets said in an exclusive interview Sunday with the AP by telephone from the United States. Shvets, also a former KGB officer, said he had known ex-Soviet spy Alexander Litvinenko, who died in London after he was exposed to a rare radioactive element, since 2002 and had spoken to him on Nov. 23, the day he died. He said he was questioned by Scotland Yard officers and an FBI agent in Washington last week. A police official in London, speaking on condition of anonymity because of the sensitive nature of the case, confirmed officers had interviewed Shvets. The official also said police expected to travel to Moscow within days, where a team of nine officers planned to interview several people, including Andrei Lugovoi, another former spy who met Litvinenko on Nov. 1 - the day he fell ill. Home Secretary John Reid said Sunday the inquiry was expanding outside of Britain and would go wherever "the police take it." Shvets declined to confirm the name of the person he had told police he believed was behind Litvinenko's death, or to offer details of a document he said he had given to the British officers. "This is first-hand information; this is not gossip. I gave them the first hand information that I have," Shvets told the AP. He said he was not prepared to disclose further details, because of concern he could disrupt the inquiry. "I want this inquiry to get to the bottom of it. Otherwise they will be killing people all over the world - in London, in Washington and in other places," Shvets said. "I want to give the police the time and space to crack this case, to allow them to find those behind this assassination, the last thing I want to do is give a warning to those who are responsible." Shvets told the AP he had met Litvinenko in 2002, when both men were investigating incidents in the Ukraine. He said Litvinenko had introduced him to Mario Scaramella, an Italian security consultant. Scaramella met Litvinenko at a central London sushi bar on Nov. 1 and has since been hospitalized. At the Center for Counterintelligence and Security Studies, in Washington, the former agent has spoken about his past as a KGB spy. Shvets, who lives in Washington, said he was currently away from his home and in the U.S. on vacation, but would not confirm his precise location because of concern for his safety. "I want to survive until the time we have a criminal case in relation to Sasha's death brought before a court in London," Shvets told the AP. In a separate statement issued through Tom Mangold, a London-based former British Broadcasting Corp. reporter and friend for 15 years, Shvets denied claims published Sunday in Britain's Observer newspaper that he had been involved in the drafting of a dossier on Russian oil company Yukos. Former Yukos shareholder Leonid Nevzlin, a Russian exile living in Israel, told the AP last week that Litvinenko had given him a document related to Yukos and said he believed the agent's killing was tied to his investigations into the company. Mangold said Shvets had denied the newspaper report, which said he had examined charges filed by Russian prosecutors against Yukos officials and shareholders, handing his findings to Litvinenko. Toxicologists found polonium-210, a rare radioactive substance, in Litvinenko's body before he died in London. Results of a post mortem examination on the 43-year-old's body are expected later this week. Scaramella was undergoing hospital tests Sunday after he showed lower levels of the same radioactive substance. University College Hospital in a statement he was well and showing no external symptoms. In an interview with Italy's RAI TG1 evening television news, Scaramella said doctors had told him that his body contains five times the dose of polonium-210 considered deadly. "So my mood isn't the best," he told the channel. At their sushi bar meeting, Scaramella told Litvinenko an e-mail he received from a source named the purported killers of Russian investigative journalist Anna Politkovskaya, who was gunned down on Oct. 7 at her Moscow apartment building. The e-mail reportedly said that he and Litvinenko - a friend of the reporter - were also on the hit list. Litvinenko reported feeling unwell on Nov. 1 and died three weeks later, his body withered, his hair fallen out and his organs ravaged. Britain's Health Protection Agency said Sunday a total of 27 people have now been referred for tests for possible radiation exposure. Reid planned to discuss the case Monday at a meeting of European interior ministers in Brussels. Litvinenko's funeral is expected to take place in London, but due to the levels of radiation in his body, the coffin will be sealed, Litvinenko's friend Alex Goldfarb said. Britain's Sunday Times newspaper quoted Lugovoi on Sunday as saying he had also been contaminated with polonium-210, a claim contradicted by a report in Russia's Kommersant newspaper on Saturday. Lugovoi was quoted as telling the Russian newspaper he and his family had tested for traces of radiation and been passed as "absolutely clean." He denied that he and two business associates, Dmitri Kovtun and Vyacheslav Sokolenko, who met Litvinenko together on Nov. 1, were involved in Litvinenko's death. "We suspect that someone has been trying to frame us," the Sunday Times quoted Lugovoi as saying. "Someone passed this stuff onto us ... to point the finger at us and distract the police." He did not say whether he had fallen ill. Repeated attempts by the AP to reach Lugovoi in Moscow through his business associate, Vyacheslav Sokolenko, have been unsuccessful.