PHILADELPHIA

Lawyers for the NFL urged a federal judge Wednesday to appoint a special investigator to look into what the league said is extensive fraud in claims on the $1 billion concussion settlement.

NFL attorneys said a study by the independent auditors in the claims process showed about 440 claims were flagged for denial based on evidence of fraud by attorneys, doctors or former players. Lawyers representing the former players and their estates said most of the opportunity for fraud has been resolved because anyone filing a claim after the settlement’s effective date has to see a neuro-specialist from a list of approved certified physicians.

The settlement, which took effect January 2017, resolved thousands of lawsuits that accused the NFL of hiding what it knew about the risks of repeated concussions.

It covers retired players who develop Lou Gehrig’s disease, dementia or other neurological problems believed to be caused by concussions suffered during their pro careers, with awards as high as $5 million for the most serious cases.

“We are talking about significant evidence of widespread fraud. We’re not talking about a difference in medical opinion,” said NFL attorney Richard Tarlowe.

Tarlowe showed evidence in fraud designations against eight doctors, two law firms and a former player. He focused on practices including doctors seeing players for evaluation not in clinical settings, but in hotel rooms, law offices or other places. He also cited a doctor who said she spent seven to 12 hours evaluating each patient, but approved sometimes as many as eight patients a day.

“That’s physically impossible based on how long she said it takes,” he said.

Three different attorneys who represent dozens of claimants spoke for the former players Wednesday. Two said they objected to the appointment of a special investigator with subpoena power and the ability to compel testimony.

They said the current structure is more than adequate for identifying fraud and not paying out claims. They also said the rules that became effective in January 2017 including the approved physicians list will greatly reduce the opportunity for fraudulent claims.