The former leader of the nation of Georgia told a Bermuda court yesterday that during the fall of the Soviet Union he had made a fortune so large that he became one of the world’s richest men.

But he trusted Credit Suisse implicitly with a billion dollars of his fortune. He testified that his only involvement with the management of the money was to check his account balances.

Bidzina Ivanishvili took the virtual witness box for the full day via video conferencing before Chief Justice Narinder Hargun, who is hearing the case in the Commercial Courts.

Mr Ivanishvili and other plaintiffs have brought claims against Credit Suisse Life (Bermuda) involving hundreds of millions of dollar losses suffered by investments in two unit-linked life insurance policies, a type of vehicle that provides for both insurance and investments.

The losses occurred after Patrice Lescaudron, a rogue banker at Credit Suisse Group AG, whose clients included Mr Ivanishvili, had invested in a company called Raptor Pharmaceutical Corp on behalf of clients.

But he used their money to purchase additional share allotments without their permission.

Raptor suffered a drastic decline in value leading to the losses. Investigations in the aftermath of the Raptor incident revealed that Lescauldron had been defrauding clients for ten years and using the proceeds to fund his extravagant lifestyle.

Bloomberg reported that the former Georgian prime minister had invested approximately $755 million in the Credit Suisse Life (Bermuda) products. His losses are estimated at about $400 million.

Testifying remotely and speaking through interpreters, Mr Ivanishvili sat at a desk in front of a large window looking over what appeared to be a small garden.

Answering questions by Credit Suisse Life (Bermuda) lawyer Stephen Moverley Smith, QC, the billionaire former leader — who, after the fall of Soviet Union, had once owned a Russian bank called Rossiysky Kredit — said: “I had experienced working in Russia and had experienced working in Georgia. In all my experience working in banks, I had never seen anything like what happened in Credit Suisse.”

He described it as “so shocking”.

Saying that he was swearing by “everything that is dear to me — my four children”, he testified that he had never encountered what he described as “the wildest capitalism that was the break-up of the Soviet Union. I have never seen the customer treated as badly, anywhere else.

“It was shock on a scale that changed my world view.”

Mr Moverley Smith questioned Mr Ivanishvili at length about his participation in the management of investments held by Credit Suisse Group and Credit Suisse Life (Bermuda).

The lawyer took Mr Ivanishvili through his progression as a client with Credit Suisse, interrogating him on his knowledge and involvement in the investments and vehicles in which the investments were held.

The former leader insisted that he was only interested in maintaining the capital sum and in the accounts’ balances. He told the court that the only requirement he had expressed to Credit Suisse was that the money was to be kept secure.

“The bank was telling us if you want to keep your money safe, you have to do this, this and this, and sign this and this.”

Mr Ivanishvili said: “We came to a trustworthy bank. We had such a big trust in them we just said, ‘Where do we sign?’ ”

He added: “Everybody and their dog has heard about the Swiss banking system and UBS. Everybody with $100,000 will go only to Switzerland because of their name. We were shying away from asking questions because it would be embarrassing, because of the reputation of the persons we were dealing with.”

Mr Moverley Smith asked the former prime minister if this was the way business was conducted in Russia.

Mr Ivanishvili replied: “Because of the break-up of the Soviet Union the environment was very volatile. You could not rely on the singular approach in Russia. The idea of trustworthiness — I might have had a similar attitude to a German or French bank. But the Swiss have the better name, even today.”

The case continues this morning.