The NFL has asked a Pennsylvania federal judge to appoint a special investigator to look into alleged “widespread fraud” that is “infecting” the $1 billion concussion litigation settlement.

The National Football League on April 13 filed a motion asking U.S. District Judge Anita Brody of the Eastern District of Pennsylvania to appoint a special investigator to look into allegations that some law firms are coaching retired players to obtain more favorable scores in the claims assessment process, and some doctors are failing to properly evaluate the claimants.

The filing comes as many lawyers are contending that the NFL and the claims administrator, BrownGreer, are improperly delaying the proceedings that are expected to compensate 20,000 former NFL players suffering concussion-related injuries.

According to the NFL's motion, which was filed by Brad Karp, of Paul, Weiss, Rifkind, Wharton & Garrison, about 46 percent of all the claims submitted under the settlement agreement have been audited because of “red flags” indicating potential fraud. The motion also said there is evidence a firm representing more than 100 retired players coached claimants and told at least one player to show up for his evaluation “hungover and on Valium.” Another firm, representing 50 ex-players, charged players more if they obtained an Alzheimer's diagnosis, and had its clients evaluated by a pediatric neurologist, the filing said.

Although the filing did not name any specific firm as being involved in the alleged fraud, the filing said that, “Ironically, some of the lawyers who are complaining most vociferously and publicly about the slow pace of claims administration are themselves associated with the submission of questionable claims and the true cause of the delay.”

“The pervasive fraud by doctors, lawyers and certain players cannot be allowed to continue,” the NFL said in the filing.

Seeger Weiss attorney Chris Seeger, who, in his role as co-lead class counsel in the litigation, is charged with overseeing the implementation of the settlement on behalf of the broad class of retired NFL players, said in an emailed statement that he agrees with the NFL that a special investigator should be appointed, and that he previously raised concerns about potentially fraudulent claims. However, he added that he did not want the NFL to use the “small number” of problematic claims to deny payment in legitimate cases.

“Unlike other NFL benefits programs, this settlement is overseen by the court, and the league cannot escape its responsibility,” Seeger said in the statement. “We will make sure that former NFL players and their families receive every benefit they are entitled to under this agreement.”

The NFL said the special investigator would supplement the claims administrator and special masters already involved in the case, as those two parties are limited in their ability to investigate potential fraud. The investigator, according to the NFL's request, should also have the ability to communicate ex parte with the court, claims administrator, co-lead class counsel and the NFL's attorneys.

The request also cited a decision by the special master late last year, which disqualified a doctor who allegedly misrepresented information involving 153 claims. That ruling said the doctor had claimed to have spent 139 hours evaluating and preparing reports for retired players during a 24-hour window.

Karp did not return a call for comment.