Does the client have a domain / business name trademarked? You can consider requesting a trademark block on that keyword.
We've done this is the past and its a long tedious process, including informing the local office in a not so subtle manner when we got tired of waiting on the US teams to get their thumbs out.
In your case, since you have an injunction against this party, try and make contact with the local office and see if they can assist. If nothing else, it informs them that they're enabling this person to violate the injunction.