A senior UBS executive who led an internal investigation into the $2.3bn unauthorised trading loss at the bank in September 2011 told a court yesterday that he would have looked into Kweku Adoboli's alleged "umbrella" further, had he known about the term.

Ruwan Weerasekera, chief operating officer for the securities division in UBS's investment bank, yesterday gave evidence for a second day at Southwark Crown Court as a witness for the prosecution in the criminal case against Adoboli, who worked at UBS until his arrest in September last year. Adoboli is charged with two counts of fraud and two of false accounting. He denies all four charges.