Investigation by who though? And at what stage of the investigation?
And where the victim does not go to the club, how do the club find out before charges are brought? Can the police inform the club or are they bound by some sort of privacy laws? Genuine question btw, Greenwoods case was unique in many ways as it was made very public while usually the accused isn't named in mainstream media, though their identity is public knowledge before long.
Whether or not it is the sensible path, the clubs need to get their act together quickly and decide on how they will deal with these allegations. Then get the lawyers on the phone because whatever they do, there probably going to end up in (civil) court themselves.