Cue the class action lawsuits...
Name the (shell) companies involved as co-defendants -- specificly noting that said companies must have their registered owners appear in court -- so that when they send in their legal teams to run interference the prosecution can simply ask the judge for a court order telling said owners to either get their asses in or have warrants for their arrest issued.
Once you've got them in court then start peppering them with all the questions you want answered -- questions they will be under oath to answer or face jail time for contempt. And if they perjure themselves under oath then they'll face even MORE prison time for pissing off the judge.
I'll get the popcorn...