Alexander Litvinenko expected to be arrested or killed after he accused Russia's spy agency of asking him to murder Boris Beresovsky, his wife Marina has told a UK court.
At the inquiry into the Russian ex-spy's death, Mrs Litvinenko spoke about how her husband lost faith in his work.
He grew disillusioned with the first Chechen War and corruption within the secret service, she said.
He told the FSB's then leader Vladimir Putin of his concerns, his widow said.
Mrs Litvinenko told the court that after a press conference in 1998 where he stated publicly that he had been asked to murder businessman Boris Berezovsky, he confided in her that he thought he would soon be killed or arrested.
It is the first time she has given evidence at the public inquiry into the death of Mr Litvinenko, who died in a London hospital in 2006 from radiation poisoning.
Two Russians, Andrei Lugovoi and Dmitry Kovtun, have denied any involvement.