(BLOOMBERG) – Credit Suisse Group AG lost a court fight in Bermuda to keep the lid on confidential reports about a deceased rogue-banker convicted of defrauding his rich clients including a billionaire former Georgian prime minister.

The Bermuda Supreme Court ruled the Swiss bank had no justification for withholding the findings of PricewaterhouseCoopers and Switzerland's banking regulator into Patrice Lescaudron's crimes, given their relevance to a trial due to open here this month.

"The bank has a direct economic interest in the outcome of these proceedings, and it seems clear that it is controlling the discovery process and indeed this litigation," Chief Justice Narinder Hargun said in a September 30 ruling.

Bidzina Ivanishvili, a former prime minister of Georgia worth an estimated $6 billion, sued Credit Suisse's Bermuda life insurance unit four years ago for alleged breaches of duty, including failing "to ensure the prudent investment of premiums."

Ivanishvili invested $755 million in life insurance products with CS Life in Bermuda and lost $400 million of it to Lescaudron's fraud, his lawyers argue.

While Ivanishvili's losses spurred lawsuits in other jurisdictions including Singapore and New Zealand, Bermuda accounts for close to half of his total losses, his lawyers say.

Credit Suisse declined to comment on the Bermuda court ruling.

When Lescaudron's fraud was exposed in 2015, Credit Suisse commissioned PwC to investigate how he could have faked trades and orders over nearly a decade to cover the growing losses he incurred on behalf of Ivanishvili and a clutch of wealthy Russian clients – without anyone knowing.

The Frenchman was convicted of fraud in 2018 but was released from prison less than a year after his conviction because of poor health.

Lescaudron, who took his own life in 2020, was a lone wolf who hid his crimes from colleagues and superiors, the Zurich-based bank has consistently said.

Ivanishvili and other plaintiffs say that his colleagues must have known about his fraudulent behaviour and if they didn't, bear criminal responsibility for failing to spot it.

The bank's refusal to share PwC's findings in the pre-trial process, known as discovery, can't be justified on the basis that it's protected by attorney-client privilege, Mr Justice Hargun said in the ruling.

Given the bank gave some of PwC's findings to the Swiss prosecutor, which were used to convict Lescaudron, "it is not readily apparent how it can be asserted that the PwC reports are privileged," he wrote.

Further, he reminded the bank that it had agreed to share PwC's findings with Ivanishvili as they became available, and pledged in a 2015 e-mail to provide him "with full transparency on what we have readily available on our systems."

The bank was also chided for failing to share with its Bermuda unit copies of a separate independent report into Lescaudron's fraud commissioned by Switzerland's banking regulator Finma, despite its obvious relevance, Mr Justice Hargun said.

Credit Suisse in April secured a UK injunction against Ivanishvili and his PR adviser who had posted a copy of the Finma report online.

CS Life has subsequently obtained a copy of the report, Mr Justice Hargun said, and there is "no sufficient reason why it should not be required to provide discovery of the document."

Ivanishvili's PR adviser and a spokeswoman for PwC both declined to comment.

A trial in the case is scheduled to open November 15 in the Supreme Court and is due to last five weeks, according to the Bermuda court's clerk.