The fabled numbered Swiss bank account is shrouded in mystery – a mystery scarcely less deep than that surrounding their holders' identity.
Bankers shut up like clams at the mere mention of these accounts, as swissinfo.ch discovered. Questions about how many there might be, or what kind of person opens one, get short shrift in Geneva, Zurich or Lugano.
In the public imagination they are associated with spies, scandals and slush funds – quite undeservedly so, according to bankers.
"These accounts are subject to exactly the same duty of diligence as any other banking relationship," UBS spokesman Dominique Gerster told swissinfo.ch.