Foreign Money Judgment

I practically chased after my ex around the globe for the child support he owed since 1999. My child support order was originated in United States in 1991 and my exfled the jurisdiction after 3 months’ paying. Ten years later, I found him working in Taiwan and brought a lawsuit to Taiwan court. My U.S. judgment was ultimately recognized after 13-months litigation process. The problem is with the execution of the judgment. What I’ve been receiving was much less than the original because: 1) my ex had prearranged other debtors to garnish his wages; 2) the third party (his employer) did not want to include interest calculation for the principle owed, even when the execution order had specifically stated it.

My questions are: Is my U.S. judgment being modified in this case, due to the inadequacy of the judicial system? Isn’t there an agency in the past or even now that processes and governs the transaction of wage garnishment generated by the employer? Is the third party (the employer) in contempt?