A former UBS trader arrested in London on charges of fraud linked with unauthorized trades that cost the Swiss bank more than $2bn pleaded not guilty Monday to the charges against him.

Kweku Adoboli, 31, pleaded not guilty to two counts of fraud and two of false accounting between 2008 and September 2011 at London's Southwark Crown Court.

The trader was arrested on Sept. 14 after on charges of committing fraud that cost the bank over $2 billion.

The incident pushed then-CEO Oswald Gruebel to resign and damaged the bank's efforts to clean up its image after being involved in a United States tax evasion investigation and sustaining huge losses on subprime mortgages during the financial crisis.

City watchdog the Financial Services Authority and its Swiss counterpart have launched an investigation into why UBS failed to spot allegedly fraudulent trading.

Adoboli's case was delayed last year after he replaced his former lawyers at Kingsley Napley law firm with a new team from Bark & Co., which specializes in fraud cases. McCreath set a provisional trial date for September 3 and remanded Adoboli in custody. He said he was willing to hear an application for bail.