Koroisau has been fined $15,000 by the NSWRL, which announced the sanctions on Wednesday afternoon, on top of the $35,000 fine and two-game suspension already issued by the NRL.
If selected again, Koroisau will need to convince the Blues board "he has earned the right to be once again trusted to uphold all of the standards, protocols and values of NSWRL".
Blues coach Brad Fittler recently said Koroisau would not necessarily have a line drawn through his name at the selection table in future.
"He broke everyone's trust and I think everyone understands that. I'm just happy it's what he does from here on in he'll be judged by," Fittler told the Sunday Footy Show. "There never is and never has been because people change from positive or negative, all different ways. It's about his reaction and how he goes from here."
The Penrith rake is due to make his return to the NRL this Saturday against the Roosters.
"When a player is selected to represent the Brydens Lawyers NSW Blues, the player is placed into a privileged position whereby he or she is trusted by the board to uphold all of the standards, protocols and values of NSWRL," NSWRL CEO David Trodden said in a statement.
"The board is extremely disappointed that in this case, the trust which was placed in Koroisau has been breached.
"If the board is to consider further recommendations for his selection in NSW teams, it will need to be convinced he has earned the right to be once again trusted to uphold all of the standards, protocols and values of NSWRL."
Koroisau has 14 days to respond to the breach notice, which he can accept or contest before a Code of Conduct hearing.
If Koroisau accepts the breach, the NSWRL proposes to donate the amount of the fine to PCYC to support its valuable youth work, particularly with the Nations of Origin tournament.
Story first published on NRL.com