Who are you in all this? Your ability to do anything about it is pretty limited unless you are the actual spouse or the putative one.

The complaint can be made to the local police. Chances are they will do NOTHING with this information. THey just don't have the inclination or resources to chase down whether even a prior US marriage was in force, let alone a foreign one.

Immigration probably isn't going to care with regard to his H1B visa. Of course, any attempt to adjust status based on the marriage or eventually to apply for naturalization, is going to very much care.