let’s imagine this scenario - Goebbels writes his diaries and instead of burying them somewhere in Berlin he mails a copy to Switzerland, rents a safe deposit box and orders papers kept for 50 years (paying ahead of time). Then WW2 is over, the OSS has in custody the people involved in delivering the papers and knows for sure when and where they ended up but the bank, when approached, says “no comment, we protect clients’ privacy”.
Would that have worked? What were the standards of Swiss bank and OSS behavior at the time?
Swiss banking laws governing bank accounts allow the Swiss government to seize money in your account if you are breaking Swiss laws. This is one of the reasons why people used Switzerland as a bank haven: Swiss laws were more permissive concerning tax fraud in another country than, say, US laws were about hiding money from the IRS. The person hiding money from the IRS could be breaking US law but not necessarily breaking Swiss law so Switzerland could tell the US “it’s not our problem.”
Also, Swiss banking secrecy was more strict in that a bank employee revealing my account information to someone would be prosecuted by the state’s district attorney, even if I don’t take the trouble to complain myself. The fines were heavy and could include jail time. So it was in a bank’s interest to make sure confidentiality was enforced amongst its employees.
Finally, it was (and still is AFAIK) possible to open a numbered bank account where only very few people in the bank (i.e. one or two people) know the identity of the person who owns the numbered bank account.
These rules only apply to bank accounts. I don’t know how the laws and bank policies for safe deposit boxes kept in a bank are different. If they are the same, then I would imagine that you would first have to prove that the person broke Swiss law. What purpose would the OSS have in demanding the diaries? Are you assuming, for example, to use as evidence in a war crimes trial such as were held in Nuremberg?
I use the diaries just as a random example of the kind of papers that the Nazi officials may have wanted to preserve - some of which could have been of greater interest than that.
Incidentally, Goebbels did not actually do that, for some reason. Even though entrusting the papers to a Swiss bank would on the face of it seem more sensible than burying them.
Well, this is just guesswork, but I don’t see a Swiss bank turning over materials in a safety deposit box just because some unrelated person says “You know, I would really like to read that.” Instead they would pass it on to the person’s legal heirs if the person was dead.