LONDON, Dec. 6, 2006 — -- British detectives investigating the poisoning death of former Russian spy Alexander Litvinenko have identified a prime suspect -- a man who also once was a Russian spy, a British official tells ABC News.
British detectives had just arrived in Moscow when they were told they could not see the man they consider their prime suspect, former KGB agent Andrei Lugovoi. He was unavailable, hospitalized with signs of radiation poisoning, Russian officials said.
Russia's top prosecutor said the British could not speak with any witnesses on their own and could not extradite them to Britain if they're charged.
"We will be asking the questions, not Scotland Yard," Russian Prosecutor General Yuri Chaika said in Russian.
Today, however, a friend of Lugovoi's says that British authorities have arranged a meeting with him. Russian authorities will also be present during that meeting.
Senior British official told ABC News the Russian government is obstructing the investigation, even as more and more signs point to Russia and Lugovoi.
ABC News has reconstructed Lugovoi's movements from Moscow to London, right up to the day he met Litvinenko at a London hotel, and found a trail of deadly polonium 210.
On Oct 25, a full week before Litvinenko was poisoned, Lugovoi flew to London. Both his plane and his hotel, the Sheraton, have tested positive for radiation.
On Oct 31, one day before the poisoning, Lugovoi returned to London. Again, his plane, his hotel -- the Millenium -- and a soccer stadium he visited all tested positive.
And today, there is word that Lugovoi himself may be contaminated.
Before he was hospitalized, Lugovoi promised to cooperate in the investigation.
"I have to, to avoid any speculation," he said in Russian.