Swiss banks are world-renowned for their secretive nature and protection of clients. Swiss banks generally have higher confidentiality than other banks, based on Swiss bank law, which regulates what information the banks can give out. In general, there is no way to trace the source of money placed on deposit with a Swiss bank; they do not routinely confirm whether a named person holds an account or not.
Due to international pressure, Switzerland has recently lowered the restrictions, and allowed international police information about suspected criminals.