After five days of hearings last week, the Court of Appeals will entertain final written submissions in an appeal of a lawsuit that saw a unit of Credit Suisse end up on the wrong side of a $600 million judgment in the Supreme Court.

And the appeals court last week raised the possibility that should the appellants succeed, the case may be sent back to the Supreme Court.

The initial trial had lasted six weeks and involved a small army of legal muscle.

The suit was brought last year by the Georgian billionaire Bidzina Ivanishvili, his family members and two associated companies against Credit Suisse Life (Bermuda).

The former Georgian prime minister was seeking relief for the massive investment losses suffered as a result of what he said was mismanagement and fraudulent activity by Credit Suisse employee Patrice Lescaudron.

In March Chief Justice Narinder Hargun awarded Mr Ivanishvili damages amounting to nearly $600 million.

His judgment concluded that the plaintiffs were victims of fraud and the Swiss bank had put revenue ahead of the interests of their clients by failing to rein in their employee.

The bank’s appeal of Mr Hargun’s decision was heard by Court of Appeal judges Jeff Bell, Anthony Smellie and the court’s president, Sir Christopher Clarke, via video link.

Baron Charlie Falconer, Britain’s former Lord Chancellor and lawyer for Credit Suisse, agreed with Sir Christopher that should the court be persuaded by his point of appeal that there was: “… no claim in contract or in tort by way of misrepresentation” then the right course might be to refer the case back to the Supreme Court to determine the entitlement of the policyholders, because he agreed with the judge that they are beneficially entitled to assets included in the premium.

He had earlier argued for the Swiss bank’s position that there had not been misrepresentation made to the tycoon on the part of Credit Suisse Life (Bermuda).

Lawyer Louise Hutton, KC, who is acting for Mr Ivanishvili, countered Lord Falconer saying Lescaudron, through his fraudulent actions in regard to his client’s Credit Suisse accounts, had falsely represented that he would manage the billionaire’s assets honestly once they were moved into policy accounts at the bank’s Bermuda offshoot, Credit Suisse Life.

Ms Hutton said that the court had found that Mr Ivanishvili received semi-annual or annual reports from Credit Suisse which informed him that his assets were performing well. “He gave evidence that on the basis of what he was told that he contemplated proposals made to him by CS Life,” she said.

She also noted that the trial court judge, Chief Justice Narinder Hargun, had agreed in his decision that in offering the policies, Lescaudron implied that there was no fraudulence or mismanagement.

This, Ms Hutton said, had allowed Mr Hargun to make his finding of inducement extended by Lescaudron to Mr Ivanishvili to buy the insurance policies. She added there was “no question” that if the representation that he was honest had not been made, the billionaire would not have entered into the policies.

She said the Chief Justice “… doesn’t need to find an awareness, a conscious awareness of Ivanishvili, that Lescaudron is telling him he isn’t committing fraud”.

The President of the Court of Appeal agreed the judges’ panel would receive the appellants’ final arguments in writing.

In a Singapore court in September, Mr Ivanishvili made similar claims that a trust unit of Credit Suisse had failed to take steps to prevent him from losing $1.27 billion.

He accused Credit Suisse Trust Ltd in Singapore of failing to safeguard his investments and "take the appropriate steps" to prevent losses linked to fraud committed by its former Geneva-based banker Lescaudron.

During the hearings, as reported by Bloomberg, the Credit Suisse Group trust lead counsel admitted before the International Commercial Court in Singapore not to have informed its billionaire client about unauthorised transfers from his accounts.

In omitting to do so, he said, the trust had failed to meet its own self-imposed standards.

A decision in that case is expected early in the new year.