It's not a government. If it was a government, they could have transported their bonds into Switzerland in a diplomatic pouch. Nor is it a company with enough clout with its own government to persuade it to transport the bonds for them.
The big question: what were the bonds doing in Italy in the first place?
Switzerland is landlocked. Only way to get there is by auto or plane. The main emphasis would have been on not implicating the bond owners. The Japanese men caught were just transporters. Doubt if they were Japanese Mafia since in Japan everyone knows who the mafia are (or perhaps that explains the media blackout - anyone see images of these two smugglers ?). Heck the mafia in Japan has offices with the mafia gang name.
The problem with transporting the bonds in a diplomat pouch is it leaves a solid trail to the owning country.