Blake is currently unregistered and is not subject to the NRL's rules or sanctions.
"Whether someone is a Rugby League player or not the actions are completely unacceptable and entirely contrary to the values of our fans and the game," NRL Chief Operating Officer, Mr Jim Doyle, said today
"In considering any future application for registration, the NRL is required to form a view as to whether someone is a fit and proper person to be registered as a player.
"Today's ruling would have to be strongly considered if any club at any level of the game was to apply for a registration on his behalf."
The NRL suspended Ferguson earlier this year for repeated alcohol offences. It reserved its position in relation to the indecent assault charges until matters could be determined in court.