A UK high court judge has slammed Credit Suisse for the way it advised and financed a Georgian businessman client in the lead up to the financial crisis, even as the Swiss bank won a lawsuit.

Justice Peter Smith dismissed the claim bought by Rosserlane and Swinbrook, companies run by Zaur Leshkasheli, a former diplomat, which alleged that the Swiss bank's M&A team had acted unlawfully when selling his interest in an oilfield in Azerbaijan.