Russian oligarch Boris Berezovsky "would not have lived long" on one million dollars, Chelsea Football Club owner Roman Abramovich told the High Court today.
Mr Abramovich told a hearing in London that Mr Berezovsky, and one of his business partners, wanted a "safety cushion" of 300 million dollars.
The court has heard that Mr Berezovsky "fled Russia, never to return" in late 2000, following a fall-out with then president Vladimir Putin - travelling initially to France, then settling in England.
Mr Abramovich said at that time he was approached by Mr Berezovsky's colleague Arkady Patarkatsishvili - who was known as "Badri" - and asked to provide the two of them with a 300 million dollar "safety cushion".
"In October or in September 2000, when Mr Berezovsky left Russia, it turned out that all his accounts had been frozen and I think all he had was one million dollars to call his own. He would not have lived long on that one million dollars," said the Russian billionaire.
"So Badri came to see me and said 'Listen, the situation is such that Boris cannot go back to Russia, so we have a request to you: please give us a large amount of money, pay us a large amount of money, and we shall keep it for a rainy day'."
He added: "He gave me this challenge from Mr Berezovsky that by the end of December, as far as I remember, he needed this 300 million dollars, then yes, he was bothered and interested as to whether I was able to do it and where I would source the money from and perhaps I would borrow some money etc, etc."
Mr Abramovich, 45, is being sued for billions by exiled Russian oligarch Mr Berezovsky, 65, in a trial before Mrs Justice Gloster at the Commercial Court in London.
Mr Berezovsky says Mr Abramovich "betrayed" him and "intimidated" him into selling shares in Russian oil company Sibneft for a "mere 1.3 billion" US dollars (£800 million) - "a fraction of their true worth".
He alleges breach of trust and breach of contract, and is claiming more than £3 billion in damages.
Mr Abramovich denies the allegations and denies that Mr Berezovsky is entitled to damages. He says Mr Berezovsky was paid millions of pounds for his services as a "political godfather" but was not a business partner.