CGX response CGX is aware of the problem with these cockroaches!
Here is the response to my question on the situation.
Quote "I can confirm that CGX is aware of this unusual trading activity and we have been in touch with GMP to discuss. We have been assured by GMP that this trading is being facilitated in this manor as per a client request. We are continuing to monitor their trading" un-quote.
It seems to have worked!!!! Good on you CGX!