WASHINGTON (Bloomberg) Four bankers who worked at Credit Suisse Group AG were charged with conspiring to help US clients evade taxes through secret bank accounts, according to an indictment yesterday and people familiar with the matter.Marco Parenti Adami, Emanuel Agustoni, Michele Bergantino and Roger Schaerer conspired with clients at “one of the biggest banks in Switzerland,” according to an indictment in federal court in Alexandria, Virginia. Zurich-based Credit Suisse, the second-biggest bank in Switzerland, is the bank, according to the people who requested anonymity.The bank’s managers in its cross-border business “knew and should have known that they were aiding and abetting US customers in evading their US income taxes”, according to the indictment.In the fall of 2008, the bank had “thousands” of accounts with $3 billion in assets not declared to the US Internal Revenue Service, according to the indictment.The scheme included setting up undeclared accounts protected by Swiss bank secrecy, providing banking and investment services in New York to holders of those accounts, and having bankers provide unlicensed banking services to customers they visited in the US, according to the indictment.“The conspiracy dates back to 1953 and involved two generations of US tax evaders including US customers who inherited secret accounts,” according to a Justice Department statement.“We are cooperating with the authorities in their investigation against these four individuals,” Marc Dosch, a bank spokesman in Zurich, said in a statement.