Bodyguard Avi Navama told the inquest Mr Berezovsky, 67, was “very depressed” in the months leading up to his death at his Mill Lane home.
He had previously lost a £3 billion claim against Chelsea Football Club owner Roman Abramovich - over how profits in the aluminium company Sibneft would be shared - and Mr Navama said Mr Berezovsky told him he was £200m in debt.
Mr Berezovky’s personal assistant, Michael Cotlick, said he had seen a change in Mr Berezovsky’s personality following the High Court case.
Detective Inspector Mark Bissell said Mr Berezovsky - born Platon Elenin - had been found hanged from a shower rail, and concluded there was no third party involvement.
However, in a statement, Berezovsky’s former wife Galina Besharova said her ex-husband did not plan to kill himself, adding she could not believe he would have committed suicide.
The inquest at Windsor Guildhall continues tomorrow.