Taken hostage for not paying his overdue taxes is one thing, taken hostage until he participates in the tax amnesty program is another thing. Yes, he may have evaded taxes or did have dirty money. So he may be a special case (but I wonder if there are other special cases out there not reported in the newspaper). According to the same news source (Kontan, fourth paragraph), he already paid the 1.8 but will not be released until his tax amnesty is approved (i.e. received his ‘Surat Pengampunan Pajak’). I think he should be released after paying his overdue taxes, and not forced to participate in the tax amnesty. After all, he can be audited whether or not he get the tax amnesty.
By the way, not ALL tax evaders are intentionally evading taxes, or their undeclared assets are obtained with dirty money. Some just made one or two honest mistakes in accounting or book-keeping, some have different point-of-view or opinion (between the tax payer and tax officials), some are simply victims of extortion (believe it or not).