Nevin Shapiro and Lloyd Lake share very special attributes.

Both were would-be sports agents, known for the nefarious tactics they employed to lure young jocks into their sphere.

Both men claimed to have corrupted the so-called amateur status of certain college athletes, Shapiro at the University of Miami, Lake at the University of Southern California. And both, in fits of vengeful pique, implicated both schools in violations that the NCAA has categorized as “a loss of institutional control.”

Both men became key witnesses in the NCAA cases against the respective universities and their coaching staffs, making allegations central, even crucial to the damaging cases against the two schools. The NCAA conferred great credibility on both of them. Without these men, there would have been no case against these two national football powers.

The two also have another common attribute: Both are convicted felons.

Lake was the great corruptor who claimed to have lavished USC All-American running back Reggie Bush (lately a Dolphin) and his family with money and gifts, in a failed attempted to get Bush to hire him as a sports agent. The NCAA, however inundated with multi-millionaire coaches and giant TV contracts, does not tolerate their unpaid athletes violating a business plan based on unpaid labor. Lake’s claims led to serious sanctions against the school and assistant football coach Todd McNair. (And to Bush returning his Heisman Trophy.)

Except that McNair, who lost his job after the NCAA charged that he knew what Lake was up to, sued for libel and slander and such. McNair’s attorney based the lawsuit on something that might have been obvious to anyone other than Javert or the ever myopic NCAA enforcement staff: The key witness possessed no more credibility than a jailhouse snitch.

Lake’s rap sheet included seven arrests. He served a prison sentence for a drug conviction. His own attorney described him as “an affiliate” with the Bloods street gang. He has been characterized in federal court as a career offender.

In his suit against the NCAA, McNair charged: “Despite a complete lack of evidence that plaintiff Todd McNair did anything wrong, let alone committed acts amounting to unethical conduct, and despite the NCAA’s own internal regulations,” McNair was sanctioned “solely upon convicted felon Lake’s incomplete responses” to “misleading and suggestive questions.”

When the NCAA’s lawyers attempted to get the lawsuit tossed in November, California Superior Court Judge Frederick Shaller said, instead, that McNair had demonstrated a probability that he could win his case. The judge called him a victim of a “malicious” and “over the top” NCAA investigation.

Those charges have a familiar ring in South Florida, where the NCAA has now admitted that its own investigators improperly paid Nevin Shapiro’s criminal attorney to help them nail UM with crippling sanctions. The NCAA investigators, in desperate need for corroborating witnesses to back up Shapiro’s claims that he had given money and gifts to UM players, paid his attorney to exploit the federal court subpoena power and depose some uncooperative actors. The pretense was that they had information pertinent to Shapiro’s case in U.S. bankruptcy court.