The following replies have been received from the offices of the grand jurists:
Grand Ayatollah Khamenei (may Allah grant him long life):
Cheating is haram and repentance (tawbah) would be sufficient.
Grand Ayatollah Makarem Shirazi (may Allah grant him long life):
He must relinquish so that another person may replace him.
Grand Ayatollah Saafi Gulpaigani (may Allah grant him long life):
Generally speaking cheating is not permissible. At present, your duty is to repent and seek divine forgiveness and that you should make up your mind not to cheat in future.