The "whole world" will finally know the truth about what happened to poisoned spy Alexander Litvinenko, his widow has said, as a public inquiry was formally opened nearly eight years after his death.
Marina Litvinenko said today was a "special" day and she is confident the inquiry into her husband's death will get under way in January, as directed by its chair Sir Robert Owen.
At a hearing at the Royal Courts of Justice today, Sir Robert formally suspended an inquest into Mr Litvinenko's death and opened a public inquiry, which was announced last week by Home Secretary Theresa May.
He praised Mrs Litvinenko for her patience in the face of "highly regrettable" delays and said the inquiry's substantive hearings will begin in January 2015.
Mr Litvinenko, who fled to Britain in 2000, died after drinking tea laced with radioactive polonium-210 while meeting two Russian men - one a former KGB officer, at the Millennium Hotel in London's Grosvenor Square. His family believes he was working for MI6 at the time and was killed on the orders of the Kremlin.
Former KGB bodyguard Andrei Lugovoi and Dmitri Kovtun have been identified as the prime suspects in the killing, but both deny any involvement and remain in Russia.
Speaking outside the court today, Mrs Litvinenko said she was confident the inquiry will start on schedule, adding: "Everybody all around the world will know the truth."
Asked if she thought last week's announcement was due to the strained political situation with Russia in the aftermath of the downing of the Malaysia Airlines flight in Ukraine, she said the "political situation" may have contributed to it, but she did not think there had been any "political involvement" in the process.
She added that she had always been aware parts of the inquiry would have to be in secret, and admitted she may never know the content of some of the evidence submitted to the inquiry, but said she was reassured it would be viewed by the chair and other lawyers.
Opening the inquiry today, Sir Robert told the hearing that alleged Russian state responsibility in the 43-year-old's death was of "central importance to my investigation".
Britain's responsibility for protecting the former KGB officer will not be investigated as part of the inquiry as there is no evidence to suggest any failings on the state's part, he told the court.
But he added that, if evidence was discovered during the course of the inquiry to suggest Britain could have prevented his death, he was able to bring the issue into the scope of the process.
Explaining that some of the inquiry will have to be kept secret and held in private, he said: "Because of the sensitivity of Her Majesty's Government's evidence it is inevitable that at least some of my final report will also have to remain secret.
"But I make it clear now that I intend to make public my final conclusions on the issue of Russian state responsibility together with as much as possible of my reasoning in that regard."
He adjourned the inquiry until September 5 when a preliminary hearing will take place, and said its substantive hearings "must begin in January 2015".
Mrs Litvinenko fought for the probe into her husband's murder after Sir Robert said he could not hold a "fair and fearless" investigation as part of an inquest, and a public inquiry should take place instead.
The Government had previously resisted launching an inquiry, instead saying it would ''wait and see'' what a judge-led inquest found, but the High Court ruled the Home Secretary should reconsider the decision.
Although Mrs Litvinenko and her lawyers will not be able to see secret material, the chairman can take it into account, unlike in an inquest.
The terms of reference for the probe are "to conduct an investigation into the death of Alexander Litvinenko in order to ascertain who the deceased was; how, when and where he came by his death; identify where responsibility for the death lies and make appropriate recommendations".
Under the Inquiries Act, Sir Robert will have the power to demand the production of witnesses and papers within UK jurisdiction, including agents and documents from the security and intelligence services. However, he has no such powers in relation to evidence from Russia.