Sweden's National Economic Crimes Unit is investigating what may be the country's largest insider trading scandal and is questioning employees of a hedge fund manager and a bank.

A spokesman for the bank, Scandinavia's Nordea, said the link to the alleged wrongdoing was minimal, but confirmed one of its employees was in custody: "The employee started here in October 2006, but the suspected insider trading took place between May 2005 and January 2006."