We cannot exchange or refund funds obtained through criminal means, as this may be interpreted as complicity in a crime. In order to continue the exchange or return the coins, we must make sure that the funds were received in an honest way
After blocking the customer's funds, such statement will not be of any benefit. You have repeatedly said that these are funds of criminal means, but so far you have not said anything clearly about how you have identified this fund and who has alleged that this fund is involved in crime. Keep this in mind you are dealing with bitcoins so don't block someone's funds with different tags, this will harm your business. I think the bitcointalk community should not use your exchange and never support you. Because this happened to the OP today, the next day something like this could happen to others.