If the NCAA’s allegations against the University of Miami’s athletic program adhered to conventional fair-trial rules, the case would be thrown out of court and the prosecutor would be reprimanded for gross incompetence.

The NCAA, however, runs its own show, makes up its own rules and answers to no one but itself, and that’s a huge problem for anyone who wants to see a fair outcome at the end of this long and painful process.

In the case against UM, the NCAA’s high-handed, self-serving process has made a mockery out of its own inquiry. UM President Donna Shalala has been clear in expressing regret for violations committed by the university. UM should not be let off the hook because of a botched investigation. That’s not fair to all the schools and athletes who play by the rules.

But the NCAA has handled this probe so poorly, in such a clumsy manner, that its own authority and integrity have been brought into question. Its discredited case against the University of Miami is tainted in a variety of ways, including the use of flagrantly unreliable witnesses, testimony coerced by bullying, and — most astounding — paying a lawyer for its chief witness and accuser to gather information it could not otherwise obtain. And that’s not in dispute — it’s what the NCAA admitted after investigating itself.

In an actual trial, a judge would have hurled a gavel at the prosecutor out of sheer frustration, but the NCAA more or less shrugged it off. After firing its vice president for enforcement, it blithely declared that it would simply ignore all the “evidence” it gathered in unethical and unprincipled ways and proceed with the rest of the case as if nothing had happened.

And — this is really rich — it went ahead and issued a so-called Notice of Allegations in which the university is accused of “lack of institutional control,” as if the NCAA’s muddled inquiry into UM’s practices had not exposed its own institutional failings.

What a mess.

Some university boosters would like “The U” sentenced to time served, and there’s a case to be made for that.

Its self-imposed penalties have included a post-season football bowl ban for two years, withholding some student athletes from competition, and forfeiting the chance to participate in a conference championship game. But letting UM determine its own punishment doesn’t seem fair, either.

At least a few of the allegations claiming that Hurricane booster Nevin Shapiro spent years showering UM sports teams, athletes and coaches with a variety of inducements that corrupted the sports program appear to be valid. These are serious charges. If true, there should be equally serious consequences, even though Shapiro is serving a 20-year sentence for a $900 million Ponzi scheme and has little credibility on his own.

At this point, the best course would be for the NCAA to move as quickly as possible to bring this case to a close. As things stand, a hearing against UM is not expected until July, and any punishment could come months later.

That’s too long. UM needs to be accountable for its actions, but the process should be expedited in a manner fair to all parties so that it can begin to recover and so athletes who weren’t at the U when all this took place won’t be punished.

After that, the NCAA must overhaul its own procedures and governance, beginning with the replacement of President Mark Emmert. The NCAA demands accountability for any violations by its members. Now it must show that it can play by the same rules.